Washington (CNN) Inside the capacious Hamburg Messe conference hall next month, President Donald Trump will come face-to-face with the man whose shadow has darkened much of his presidency: Vladimir Putin.

The two men have not met in person since Trump entered office five months ago under a cloud of suspicion about his campaign's ties to Russia

Trump has yet to raise the issue of election meddling with the man who US intelligence officials say personally ordered and closely monitored attempts to influence last year's presidential contest in Trump's favor.

And while both the White House and the Kremlin say there have been no formal preparations for sit-down talks, there's little doubt among officials in both countries that Trump and Putin will interact when they both attend the Group of 20 talks, held this year in the northern German city at the beginning of July.

On the sidelines of last year's G20, Trump's predecessor Barack Obama confronted Putin over the cyberhacking, but the damage had largely been done. This year, Trump will find himself under pressure to raise the issue again -- but had shown few signs that he's willing to accuse Putin of taking steps that were meant to help him win the presidency.

Since Trump's inauguration, hopes have dimmed for a reset in ties between the two countries amid new disputes over Syria and Ukraine. Trump has vowed to seek out new areas of cooperation with Moscow, but has instead overseen a rise in tensions.

US and Russian officials this week have scaled up their rhetoric, placing new frost on the relationship.

Monday, Moscow threatened to down US fighter jets battling ISIS in retaliation for a US shoot-down of a Syrian government warplane.

And Wednesday, Russia said it was canceling talks with US officials meant to improve relations between the two countries, claiming Washington had scuttled chances for cooperation.

Those are on top of the already-existing dispute between the US and Russia over last year's election hacking. This week, Jeh Johnson, the top homeland security official under Obama said that Putin had directed the cyber attacks himself.

"In 2016, the Russian government, at the direction of Vladimir Putin himself, orchestrated cyberattacks on our nation for the purpose of influencing our election -- plain and simple," Johnson said at a House intelligence committee hearing.

Meanwhile, multiple investigations into Trump associates' contacts with Russian officials are proceeding apace , a swirl of controversy that has preoccupied Washington, including Trump himself. Any talks between the two leaders in Hamburg will occur with the Russia cloud as their backdrop, even as the White House has tried to move on.

"I think that we will meet at some point, that's for sure," Putin told the American film director Oliver Stone in an interview aired on Showtime this month. "But we are not pressing anyone for a meeting."

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'We cannot exclude the possibility'

At the White House on Friday, press secretary Sean Spicer said a meeting between Presidents Trump and Putin is possible on the sidelines of the G20.

"We have a lot of countries the we will probably have bilaterals with on the sidelines of the G20," Spicer told reporters at an off-camera briefing. "I think that he understands that we have a role -- to the extent that we can work with Russia to solve some problems and to cooperate. If we can find that willingness then we would like to do it."

Speaking from Moscow on Wednesday, Kremlin spokesman Dmitry Peskov said in response to a question from CNN that a meeting between the two leaders at the G20 summit is "not being prepared in any way."

"We cannot exclude the possibility that in one way or another, they will of course meet each other in some or the other format on the sides of the summit," Peskov went on. "But there are no specific agreements or preparations so far."

A senior Trump administration official also said there were no formal plans for Trump and Putin to meet in Hamburg, where the leaders of 20 of the world's richest nations will gather for the yearly conference.

But officials in both countries suggested that, at a minimum, an informal meeting between Trump and Putin is likely, akin to the pull-aside talks that President Barack Obama conducted with Putin at the past two G20 meetings, in Antalya, Turkey, and Hangzhou, China.

"It would be hard for them to avoid each other," said one US official familiar with plans for the summit.

Still, the lack of formal preparations hasn't curtailed global anticipation.

"If you ask me what the highlight of the G20 summit will be, I would reply that it will be the meeting of Putin and Trump, if it takes place," said Alexy Pushkov, the chairman of the Information Policy Committee in Russia's upper house of parliament, during a visit to Berlin on Tuesday.

"Trump, being under pressure from his political opponents, has had no opportunity to meet with Vladimir Putin," Pushkov said, according to the TASS Russian news agency. "I think that a lot will depend on this meeting, that is why it is so highly anticipated everywhere -- from Tallin to Lisbon, from Beijing to Cairo."

When Trump and Putin do eventually meet, leaders in capitals around the world will be closely eyeing the session for clues about the dynamic between the two men. Putin and Obama had a notoriously icy relationship that accompanied a steep decline in relations between the US and Russia.

Photos: President Trump's first foreign trip President Donald Trump and first lady Melania Trump board Air Force One on Saturday, May, 27, 2017, at Naval Air Station Sigonella in Italy. They were headed back to the United States after a nine-day trip to the Middle East and Europe. Hide Caption 1 of 69 Photos: President Trump's first foreign trip President Trump greets people on May 27, after speaking to US troops at Naval Air Station Sigonella. Hide Caption 2 of 69 Photos: President Trump's first foreign trip President Trump addresses US troops and their families on May 27, at the Sigonella Naval Air Station. Hide Caption 3 of 69 Photos: President Trump's first foreign trip President Trump and first lady Melania Trump arrive on May 27, to address US military personnel and families at Naval Air Station Sigonella. Hide Caption 4 of 69 Photos: President Trump's first foreign trip Leaders of the G-7 and some African nations pose for a photo on May 27, on the second day of the G-7 summit in Taormina, Italy. Hide Caption 5 of 69 Photos: President Trump's first foreign trip President Trump gestures on May 27, during a G-7 session. Hide Caption 6 of 69 Photos: President Trump's first foreign trip President Donald Trump and his wife, Melania, arrive for a concert of the La Scala Philharmonic Orchestra while in Taormina, Italy, on Friday, May 26. The Trumps are in Italy for a two-day G-7 summit. Hide Caption 7 of 69 Photos: President Trump's first foreign trip Trump and other leaders pose for a group photo at the G-7 summit on May 26. From left are European Council President Donald Tusk, Canadian Prime Minister Justin Trudeau, German Chancellor Angela Merkel, Trump, Italian Prime Minister Paolo Gentiloni, French President Emmanuel Macron, Japanese Prime Minister Shinzo Abe, British Prime Minister Theresa May and European Commission President Jean-Claude Juncker. Hide Caption 8 of 69 Photos: President Trump's first foreign trip Trump and Trudeau walk together after the group photo. Hide Caption 9 of 69 Photos: President Trump's first foreign trip G-7 leaders congregate during a walking tour on May 26. Hide Caption 10 of 69 Photos: President Trump's first foreign trip Trump embraces new French President Emmanuel Macron on May 26. Hide Caption 11 of 69 Photos: President Trump's first foreign trip The leaders watch a French air squadron. Hide Caption 12 of 69 Photos: President Trump's first foreign trip Melania Trump arrives at the City Hall in Catania, Italy, on May 26. She was wearing a $51,500 Dolce & Gabbana jacket as she met with other spouses of G-7 leaders. Hide Caption 13 of 69 Photos: President Trump's first foreign trip Trump shakes hands with Macron in Brussels, Belgium, on Thursday, May 25. They were attending a NATO summit as the alliance officially opened a new $1 billion headquarters. Hide Caption 14 of 69 Photos: President Trump's first foreign trip Trump stands with other world leaders during a NATO photo shoot on May 25. Hide Caption 15 of 69 Photos: President Trump's first foreign trip Trump speaks with British Prime Minister Theresa May during a working dinner at NATO headquarters. Hide Caption 16 of 69 Photos: President Trump's first foreign trip Trump stands next to German Chancellor Angela Merkel at the NATO summit. Hide Caption 17 of 69 Photos: President Trump's first foreign trip Melania Trump visits the Magritte Museum in Brussels with Amelie Derbaudrenghien, partner of Belgian Prime Minister Charles Michel. Hide Caption 18 of 69 Photos: President Trump's first foreign trip A girl takes a selfie with Melania Trump at a children's hospital in Brussels on May 25. Hide Caption 19 of 69 Photos: President Trump's first foreign trip Trump meets with Macron in Brussels. Hide Caption 20 of 69 Photos: President Trump's first foreign trip Trump walks with European Council President Donald Tusk, center, and European Commission President Jean-Claude Juncker, right, after they met at the European Council in Brussels on May 25. Hide Caption 21 of 69 Photos: President Trump's first foreign trip Trump, third from right, attends a meeting with leaders at the European Council. Hide Caption 22 of 69 Photos: President Trump's first foreign trip Trump speaks with King Philippe of Belgium as Queen Mathilde and Melania Trump chat during a reception at the Royal Palace in Brussels on Wednesday, May 24. Hide Caption 23 of 69 Photos: President Trump's first foreign trip Tusk talks to Trump as he welcomes him in Brussels. Hide Caption 24 of 69 Photos: President Trump's first foreign trip Trump stands with Belgian Prime Minister Charles Michel while the national anthem is played during Trump's arrival in Belgium on May 24. Hide Caption 25 of 69 Photos: President Trump's first foreign trip Protesters in Brussels demonstrate with effigies of Trump and Michel on May 24. Hide Caption 26 of 69 Photos: President Trump's first foreign trip Trump shakes hands with Italian President Sergio Mattarella in Rome on May 24. Hide Caption 27 of 69 Photos: President Trump's first foreign trip Pope Francis stands with Trump and his family during a private audience at the Vatican on May 24. Joining the President, from left, are Trump's son-in-law, White House senior adviser Jared Kushner; Trump's daughter and adviser Ivanka Trump; and first lady Melania Trump. Hide Caption 28 of 69 Photos: President Trump's first foreign trip Trump and the Pope exchange gifts. Trump presented the Pope with a first-edition set of Martin Luther King's writings. The Pope gave Trump an olive-tree medal that the Pope said symbolizes peace. Hide Caption 29 of 69 Photos: President Trump's first foreign trip Trump and his wife look at the ceilings of the Sistine Chapel. Hide Caption 30 of 69 Photos: President Trump's first foreign trip Trump speaks to reporters in Rome during a meeting with Italian Prime Minister Paolo Gentiloni, right, on May 24. Hide Caption 31 of 69 Photos: President Trump's first foreign trip The first lady visits a pediatric hospital in Vatican City on May 24. Hide Caption 32 of 69 Photos: President Trump's first foreign trip Melania Trump arrives at the Vatican on May 24. With Vatican protocol in mind, she wore a black veil and long-sleeved black dress draped down to her calf. Ivanka Trump wore a similar outfit with a larger veil. Hide Caption 33 of 69 Photos: President Trump's first foreign trip President Trump and Israeli Prime Minister Benjamin Netanyahu wave at the Israel Museum in Jerusalem on Tuesday, May 23. Trump gave a speech there, reaffirming his country's commitment to Israel while also holding up Judaism's historical ties to the United States. Hide Caption 34 of 69 Photos: President Trump's first foreign trip People take pictures of the message Trump wrote at Yad Vashem, the Holocaust memorial in Jerusalem, on May 23. Hide Caption 35 of 69 Photos: President Trump's first foreign trip With the help of US Marines, Trump and his wife lay a wreath at Yad Vashem. Hide Caption 36 of 69 Photos: President Trump's first foreign trip Trump meets with Mahmoud Abbas, the President of the Palestinian Authority, on May 23. Trump met with Israeli leaders the day before and said he believes both sides "are ready to reach for peace." Hide Caption 37 of 69 Photos: President Trump's first foreign trip A Palestinian security official takes position before the arrival of Trump's convoy in Bethlehem, West Bank. Hide Caption 38 of 69 Photos: President Trump's first foreign trip Israeli and American activists hold signs Monday, May 22, during an anti-Trump protest next to the US embassy in Tel Aviv, Israel. Hide Caption 39 of 69 Photos: President Trump's first foreign trip Melania Trump and Israeli first lady Sara Netanyahu speak to children during their visit to the Hadassah hospital in Jerusalem on May 22. Hide Caption 40 of 69 Photos: President Trump's first foreign trip Trump talks to reporters as he meets with Israeli Prime Minister Benjamin Netanyahu on May 22. Trump sought to rebut claims that he damaged Israeli intelligence capabilities by revealing highly classified information to Russian operatives earlier this month. "Just so you understand, I never mentioned the word or the name Israel," Trump told reporters as he began the second leg of his first foreign tour. Hide Caption 41 of 69 Photos: President Trump's first foreign trip Trump touches the Western Wall, Judaism's holiest prayer site, while in Jerusalem on May 22. Trump became the first sitting US president to visit the wall. Hide Caption 42 of 69 Photos: President Trump's first foreign trip Trump stands in the Western Wall plaza. To his left, in black, is Shmuel Rabinowitz, the rabbi of the Western Wall. Hide Caption 43 of 69 Photos: President Trump's first foreign trip First lady Melania Trump, in white, visits the Western Wall. At far left is Ivanka Trump. Hide Caption 44 of 69 Photos: President Trump's first foreign trip The President and first lady plant a tree in Jerusalem with Israeli President Reuven Rivlin. Hide Caption 45 of 69 Photos: President Trump's first foreign trip Trump is welcomed by Netanyahu upon arriving in Tel Aviv on May 22. Trump started his trip with two days in Saudi Arabia. Hide Caption 46 of 69 Photos: President Trump's first foreign trip On the way to Tel Aviv, US Secretary of State Rex Tillerson speaks with reporters aboard Air Force One. Hide Caption 47 of 69 Photos: President Trump's first foreign trip While in Riyadh, Saudi Arabia, Trump attends the inauguration ceremony for the Global Center for Combating Extremist Ideology. Joining him here are Saudi King Salman bin Abdulaziz Al Saud, center, and Egyptian President Abdel Fattah el-Sisi, left. Hide Caption 48 of 69 Photos: President Trump's first foreign trip Trump speaks in Riyadh during the Arab Islamic American Summit on Sunday, May 21. Trump looked to make it clear that the United States is not at war with Islam. "This is not a battle between different faiths, different sects or different civilizations," he said. "This is a battle between barbaric criminals who seek to obliterate human life, and decent people of all religions who seek to protect it. This is a battle between good and evil." Hide Caption 49 of 69 Photos: President Trump's first foreign trip Trump sits at the summit, which included leaders from 55 Muslim-majority countries. He urged them to do more to eradicate terrorist groups that claim the mantle of Islam. "We can only overcome this evil if the forces of good are united and strong and if everyone in this room does their fair share and fulfills their part of the burden," Trump said. "Muslim-majority countries must take the lead in stamping out radicalization." Hide Caption 50 of 69 Photos: President Trump's first foreign trip Trump poses with other leaders at the Arab Islamic American Summit. Hide Caption 51 of 69 Photos: President Trump's first foreign trip Saudi King Salman shakes hands with Trump on May 21. Trump is the first US president to start his first foreign trip in the Middle East. Hide Caption 52 of 69 Photos: President Trump's first foreign trip Trump meets with other heads of state in Riyadh on May 21. Hide Caption 53 of 69 Photos: President Trump's first foreign trip Trump speaks with the Crown Prince of Abu Dhabi, Gen. Sheikh Mohammed Bin Zayed Al Nahyan. Hide Caption 54 of 69 Photos: President Trump's first foreign trip First lady Melania Trump chats with children during a visit to the American International School in Riyadh on May 21. Hide Caption 55 of 69 Photos: President Trump's first foreign trip While in Riyadh, President Trump meets with Bahrain's King Hamad bin Isa Al Khalifa on May 21. Hide Caption 56 of 69 Photos: President Trump's first foreign trip President Trump and Egyptian President Abdel Fattah el-Sisi share a laugh during a meeting on May 21. El-Sisi complimented Trump on his "unique personality that is capable of doing the impossible." Trump exchanged pleasantries back, praising el-Sisi's shoes. Hide Caption 57 of 69 Photos: President Trump's first foreign trip Trump is handed a sword during a welcoming ceremony at Riyadh's Murabba Palace on Saturday, May 20. Hide Caption 58 of 69 Photos: President Trump's first foreign trip Trump sits with members of his staff and Cabinet before a meeting with Saudi King Salman on May 20. Hide Caption 59 of 69 Photos: President Trump's first foreign trip Trump and King Salman take part in a signing ceremony at the Saudi Royal Court in Riyadh on May 20. The two leaders oversaw the signing of a defense deal worth nearly $110 billion. Hide Caption 60 of 69 Photos: President Trump's first foreign trip The Trumps look at a display of modern art at the Saudi Royal Court in Riyadh. Hide Caption 61 of 69 Photos: President Trump's first foreign trip King Salman presents Trump with a gilded necklace and medal, the country's highest honor. The distinction also was bestowed upon Presidents Barack Obama and George W. Bush. Hide Caption 62 of 69 Photos: President Trump's first foreign trip The first lady chats with Saudi Crown Prince Muhammad bin Nayef at the medal ceremony on May 20. Hide Caption 63 of 69 Photos: President Trump's first foreign trip Ivanka Trump attends the medal ceremony. Hide Caption 64 of 69 Photos: President Trump's first foreign trip Trump meets with King Salman after arriving in Riyadh on May 20. Hide Caption 65 of 69 Photos: President Trump's first foreign trip Soldiers on horseback carry the US and Saudi flags as they escort Trump to the Saudi Royal Court in Riyadh. Hide Caption 66 of 69 Photos: President Trump's first foreign trip Trump is welcomed by King Salman after arriving at the King Khalid International Airport in Riyadh. Hide Caption 67 of 69 Photos: President Trump's first foreign trip The Trumps take part in the welcome ceremony. Hide Caption 68 of 69 Photos: President Trump's first foreign trip The President and first lady wave from Air Force One after landing in Riyadh. Hide Caption 69 of 69

New era?

Moscow hoped Trump would usher in a new era of relations. Russian officials were cheered by Trump's praise of Putin on the campaign trail, and his expressed desire to find ways to cooperate in battling terrorism.

Despite a parade of foreign leaders to Trump's White House, however, no invite has been extended to Putin. Trump did hold an Oval Office meeting with Russian Foreign Minister Sergey Lavrov and Russian Ambassador to the US Sergey Kislyak, and photos taken by Russian state media showed a jovial reception

But there's little sign the Trump administration plans to drop the Obama-era positions that spurred new enmity between the Cold War-era rivals. The US has maintained that Syrian leader Bashar al-Assad must leave power, a stance Russia argues violates Syrian sovereignty. And the Trump administration has shown no signs it will let up on its demands that Russian forces leave Eastern Ukraine, even though Trump himself suggested during the campaign that Russia had not annexed the Crimean peninsula.

"Until they are out of Eastern Ukraine, we're going to continue to have sanctions on Russia," White House press secretary Sean Spicer told reporters on Wednesday.

This week, Ukrainian President Petro Poroshenko met at the White House with Trump in an attempt to color his thinking on the conflict ahead of the US president's first interaction with Putin. Speaking with reporters, Poroshenko said he was eager to get in Trump's ear before the Russian president.

"It is very important that my meeting ... will be earlier than Putin's meeting," Poroshenko said, according to an official presidential news service, adding that it was necessary for "everyone to be armed with information."

The appeals seemed to work, at least for now. The US tightened sanctions on Russia Tuesday in a bid to force the end of its occupation of Crimea, prompting the angry cancellation of planned talks between officials that were scheduled for this week.

"After yesterday's decision on sanctions, the situation does not allow for a round of such a dialogue, especially as there is no content for it, since Washington didn't offer nor is offering now anything specific," the Russian Foreign Ministry said.

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Russian election meddling

What's less clear is how Trump plans to confront Putin about Russia's meddling in last year's election contest. During his talks with Putin at last year's G20 in China, Obama said he told the Russian leader to "cut it out" and that "there were going to be some serious consequences if he did not," according to his own account of the interaction.

Trump, who remains deeply sensitive about suggestions that Russia somehow helped win him the presidency, hasn't spoken at length about the meddling, though he has kept in place economic sanctions placed on Russia in response to the hacking.

For Putin, who has denied all allegations that his government oversaw a widespread attempt to sway the US political contest, a meeting could act as a way to feel out Trump on the issue.

"President Trump needs to shape his stance on key issues in coordination with his partners," Putin told Oliver Stone in the televised interview. "I hope that we will be able to find common ground, so that we can understand each other. We need to launch a substantial dialogue with the US side."