This weekend brought the remarkable news that President Donald Trump went to extreme lengths to conceal or limit access to information about his in-person meetings with Russian President Vladimir Putin.

As first reported by the Washington Post, Trump has blocked the rest of his administration from receiving briefings about his conversations with Putin, once going so far as to take possession of the notes of the U.S. interpreter present. Details about these unusual, unprecedented actions are renewing calls among congressional Democrats to try to obtain notes or testimony from the interpreter, as well as State Department records of the Trump-Putin encounters.

The two world leaders have interacted face-to-face in five different locations since Trump took office in January 2017. Sometimes they’ve sat down for extensive private conversations; other times they’ve just exchanged words in full view of press cameras. More than one of those meetings have coincided with fraught moments in the federal investigation into Russia’s interference in the 2016 presidential election. Per the Post, no substantial record of any of them exists.

Foreign policy experts say that these off-the-record encounters leave the rest of the U.S. national security apparatus in the dark about how to navigate the country’s relationship with Russia, allow Russia to control public perceptions of the talks, and leave Trump more vulnerable to manipulation from Putin.

An outraged Trump denied that he was doing Russia’s bidding in interviews over the weekend, saying the content of his meetings is “open for grabs.” Speaking on background, administration officials have said he limited access to details of the conversations to curb embarrassing leaks.

TPM rounded up what we know about the five face-to-face meetings between Putin and Trump.

July 2017: Trump accepts Putin denials of Russian meddling

Where was it: Sidelines of G-20 summit in Hamburg, Germany

Who was there:

Formal meeting: Trump, Putin, Russian foreign minister Sergei Lavrov, then-Secretary of State Rex Tillerson, unidentified interpreters from U.S. and Russia, unidentified U.S. linguist

Dinner conversation: Trump, Putin, Putin’s interpreter

What happened: Weeks after President Trump ousted James Comey from the FBI and Robert Mueller was appointed to oversee the investigation into Russia’s election interference, Trump and Putin met in person for the first time. The leaders skipped the G-20 panel on climate change to hold a sit-down that was scheduled to last 45 minutes but ended up running for over two hours.

The key points of emphasis depend on who you ask. Tillerson, who shared a readout and spoke to reporters at a news conference following the meeting, said that the two sides spoke about the war in Syria and that Trump “pressed President Putin on more than one occasion regarding Russian involvement” in the 2016 campaign. Lavrov said both leaders expressed a desire for mutually beneficial agreements and reduced tensions between the two countries. According to reports, the interpreter told other administration officials that Putin denied Russia’s interference in the U.S. election and Trump replied, “I believe you.”

U.S. officials received no formal readout. The Post reported that Trump actually confiscated the notes of his own interpreter, and instructed the linguist present not to discuss the content of the conversation with other administration officials.

That night, the two officials spoke again for “nearly an hour” at a dinner hosted by German Chancellor Angela Merkel. The initially undisclosed conversation occurred in full view of other world leaders, but with only Trump, Putin and Putin’s interpreter present.

While the White House downplayed the “brief conversation,” Trump later told the New York Times that Putin talked to him about “Russian adoption.” Russia’s ban on Americans adopting Russian children was implemented to retaliate against U.S. sanctions on Russian officials believed to have committed human rights abuses.

The following day, as Trump flew back to the U.S. on Air Force One, he reportedly personally dictated a false statement related to the very same subject. The misleading statement said that adoptions were the main focus of a June 2016 Trump Tower meeting Donald Trump Jr. and other Trump campaign staffers held with a Russian lawyer, who had actually promised dirt on Hillary Clinton.

November 2017: A friendly encounter following Mueller’s first indictments

Where was it: Annual Asia-Pacific Economic Cooperation summit in Vietnam

Who was there: Trump, Putin, large entourages for each world leader

What happened: Both Trump and Russian officials predicted that the U.S. and Russian presidents would convene for a formal meeting at this annual economic summit, with Russian presidential aide Yuri Ushakov suggesting Nov. 10 was the agreed-upon date. On Air Force en route to Asia, Trump told reporters that he “expected” to meet with Putin since he wanted the Russian president’s “help on North Korea.”

But “scheduling conflicts on both sides” prevented a formal meeting from taking place at the two-day gathering, Sarah Huckabee Sanders later said.

The two leaders did speak informally on several occasions during the summit, as CNN documented. They chatted animatedly while walking to a photo-op, spoke again briefly before one of the conference’s sessions, and met briefly a third time during a second photo-op with the other heads of state in attendance.

These chummy conversations happened the week after Mueller issued his first indictments, charging former Trump campaign chairman Paul Manafort and campaign adviser Rick Gates for matters related to their illegal foreign lobbying.

July 2018: Trump casts doubt on Russian election meddling at explosive Helsinki summit

Where was it: 2018 U.S.-Russia summit at the presidential palace in Helsinki, Finland

Who was there:

At one-on-one meeting: Trump, Putin, U.S. interpreter Marina Gross, an unidentified interpreter for Russia

At a subsequent working lunch: Trump, Putin, interpreters, National Security Council senior Russia adviser Fiona Hill, national security adviser John Bolton, U.S. Ambassador to Russia Jon Huntsman Jr., then- White House Chief of Staff John F. Kelly, Lavrov, Russian Ambassador to the U.S. Anatoly Antonov, Ushakov, Kremlin Press Secretary Dmitry Peskov

What happened: Ahead of the much-heralded Trump-Russia summit in Finland, Mueller indicted 12 Russian intelligence officers for hacking the computer networks of Hillary Clinton campaign staffers, the Democratic National Committee and the Democratic Congressional Campaign Committee — and coordinating the public release of the damaging information they obtained.

These blockbuster revelations prompted Senate Minority Leader Chuck Schumer (D-NY) to urge Trump to call off his meeting with Putin. But Trump went forward with the planned meeting, and took steps to keep his conversation quiet.

No Cabinet officials or aides were allowed in the room while Trump and Putin spoke for two hours in private. The Post reported that Trump’s interpreter, Marina Gross, emerged with “pages of notes.”

The two leaders then went into a working lunch with other senior U.S. and Russian officials, where they continued to discuss the Syrian civil war and other foreign policy issues.

Then came the stunning press conference. With the world watching, Trump questioned U.S. intelligence agencies’ conclusion that Russia interfered in the 2016 election and said he didn’t “see any reason” to disbelieve Putin’s claims that his country did nothing wrong. Trump even praised Putin’s “incredible” offer to have Russian investigators assist Mueller with his probe.

Trump’s performance was met with shock from Democratic lawmakers, rare criticism from some of their Republican colleagues, and denials from the intelligence community, who reiterated that Russia was behind the cyberattacks. Director of National Intelligence Dan Coats later conceded that he did not “know what happened in that meeting” behind closed doors.

The White House then publicly discussed welcoming Putin to D.C. for a summit before scrapping the plan in the face of intense criticism.

Nov 2018: A brief hello in Paris

Where was it: 100-years anniversary of armistice ending World War I, Paris, France

Who was there: Trump, Putin, other world leaders

What happened: Kremlin spokesman Dmitry Peskov and John Bolton told the press that the leaders planned to hold a bilateral meeting on the sidelines of a World War I memorial celebration in Paris. The plan was to discuss Trump’s plans to withdraw from the Intermediate-Range Nuclear Forces Treaty.

But Putin subsequently told the state-owned RT news channel that France urged him not to distract from the purpose of the event by holding an attention-grabbing meeting with Trump. Putin told RT that the pair did still have a chance to talk.

Photos from one lunch at the Elysee Palace showed the leaders sitting across from each other, and other wire images showed them shaking hands and Putin flashing a “thumbs up” sign at Trump as they gathered with other leaders for a ceremony near the Arch de Triomphe.

Dec 2018: An informal meeting despite tensions over Ukraine

Where was it: Sideline conversations at the G-20 summit in Buenos Aires, Argentina

Who was there: Trump, Putin, other world leaders

What happened: Trump and Putin were set to discuss security issues, arms control, trade and issues in the Middle East and Ukraine at the G-20, with the Kremlin predicting a “long and thorough” conversation.

But the planning was thrown off when Russia opened fire on Ukrainian boats in late November, seizing the vessels and their crews near Crimea. Trump said he might call the meeting off, saying he didn’t “like that aggression.” Moscow insisted an “impromptu” discussion would still happen, and a round of will-they-or-won’t-they reporting ensued.

No formal meeting ended up occurring. But the White House confirmed that the pair had an “informal” conversation at a cultural dinner at the Teatro Colón theater attended by other world leaders and their wives. Bloomberg reported that they briefly discussed the naval confrontation in Ukraine. Putin told reporters that the pair had another brief meeting the following day on the same topic, saying, “He has his position. I have my own. We stayed in our own positions.”