The chief of staff Gen. Joe Dunford Jr. is meeting with Russia's top military officer this week for the first such meeting in three years.

Pentagon and Moscow leaders have not met in person since Russia's annexation of Crimea in 2014 - which sparked international outcry.

But with rapidly escalating tensions between the U.S. and Russia, Dunford Jr., chairman of the Joint Chiefs of Staff, will hold talks with Valeriy Gerasimov, the chief of the general staff of Russia's armed forces, in Baku, Azerbaijian, on Thursday.

The meeting follows a series of belligerent moves by their military as Moscow which appears to be testing the resolve of Donald Trump's young presidency - including buzzing a US destroyer and allowing a Russian spy ship to 'loiter' near a submarine base.

Gen Dunford Jr., chairman of the Joint Chiefs of Staff, (left) will hold talks with Valeriy Gerasimov, the chief of the general staff for Russia, in Baku,(right) Azerbaijian

Today Donald Trump's defense secretary James Mattis rejected Vladimir Putin's calls for closer collaboration with the U.S. military to fight terrorism.

The Russian president had said it was in the 'general interest' for improved information sharing between services.

'We are not in a position right now to collaborate on a military level. But our political leaders will engage and try to find common ground,' Mattis told reporters after talks at NATO headquarters in Brussels.

U.S. Secretary of State Rex Tillerson and Russian Foreign Minister Sergey Lavrov also met for the first time in the highest-level face-to-face contact between the two countries since President Donald Trump took office.

US Secretary of State Rex Tillerson (right) and Russian Foreign Minister Sergey Lavrov (left) have met for the first time in the highest-level face-to-face contact between the two countries since President Donald Trump took office.

Lavrov was asked if Russia is concerned about turmoil in the Trump administration. He repeated Moscow's standard line that Russia 'does not interfere in the domestic matters of other countries.'

RUSSIA TESTS TRUMP'S RESOLVE: A TIMELINE February 10: Four Russian military aircraft buzzed a U.S. destroyer, USS Porter, in the Black Sea February 14: Spy ship SSV-175 Viktor Leonov is spotted 70 miles off the East Coast February 14: Moscow secretly deploys a new cruise missile despite landmark arms control treaty February 15: Leonov is seen 30 miles away from Naval Submarine Base New London, Connecticut Advertisement

Tillerson did not speak at the meeting on the sidelines of a conference of foreign ministers of Group of 20 major powers in Bonn, Germany.

Moscow is hoping Trump makes good on his pledge to improve ties with Russia and seek cooperation in the fight against ISIS.

'Even a simple exchange of information about the channels and sources of terrorists, about people implicated in or suspected of terrorism seriously raises the effectiveness of our joint efforts,' Putin said.

But President Trump is currently facing questions over Moscow's influence on the White House. They follow allegations from the US intelligence community that Putin ordered a hacking and influence campaign to help get Trump elected.

This week his national security adviser, Michael Flynn, resigned after it emerged he had made misleading statements he over conversations he'd had with the Russian ambassador.

The spy ship was seen just 30 miles away from the Naval Submarine Base New London, known as the 'Home of the Submarine Force', in Groton, Connecticut

The intelligence-gathering ship Viktor Leonov has been spotted on and off around the East Coast over the past few years (pictured in Havana in 2014)

Four Russian military aircraft conducted low passes against a U.S. destroyer in the Black Sea just days before a spy ship was spotted off the East Coast (stock image)

It has prompted growing criticism over Moscow's influence on the White House.

Yesterday a Russian spy ship was spotted loitering just 30 miles off the coast of a Naval submarine base in Connecticut - the latest in series of belligerent moves by their military as Moscow appears to be testing the resolve of Donald Trump's young presidency.

The SSV-175 Viktor Leonov ship moved even closer to the East Coast, after it was spotted 70 miles off the coast of Delaware on Tuesday, Fox News reports.

While it remains in international waters, a U.S. official said the armed boat - capable of intercepting communications and sonar capability - is 'loitering'.

Russia has also deployed a new cruise missile apparently violating an arms control treaty banning ground-based U.S. and Russian intermediate-range missiles.

The nation has secretly deployed the ground-launched SSC-8 cruise missile that Moscow has been developing and testing for several years, despite U.S. complaints that it violated sections of the 1987 Intermediate-range Nuclear Forces treaty, The New York Times reported.

Trump (far left) demanded the resignation of Michael Flynn (far right), his national security adviser for talking to the Russian ambassador, this week

Putin recently called for the US and Russia to work together to fight terrorism (file above of Russian President Vladimir Putin)

And days earlier, four Russian military aircraft conducted low passes against a US destroyer in the Black Sea.

The USS Porter, a guided missile destroyer, reported the aircraft performing 'dangerous flybys' past the ship which was based just off the coast of Romania on February 10.

'There were several incidents involving multiple Russian aircraft,' said Navy Capt. Danny Hernandez, spokesman for the European Command. 'They were assessed by the commanding officer as unsafe and unprofessional.

WHAT ARE THE LATEST RUSSIAN REPORTS? High-level staffers on Trump's team and some aides were in 'constant communication' with Russian intelligence during the campaign One person has been named - former campaign chairman Paul Manafort President-elect Trump and President Obama were briefed on the contact Communication 'raised a red flag' - especially because Trump often spoke highly of Putin in public Communications were uncovered in call records and intercepted conversations Russian officials spoke about having 'special access to Trump' Information was found during 'routine US intelligence collection' - and not because Trump's team was targeted The FBI and intelligence officials are still trying to figure out why the communication was taking place Advertisement

Trump's predecessor Barack Obama slapped sanctions on Russia's FSB domestic agency and the GRU military intelligence over accusations they were involved in cyberattacks against the US.

The comments come as a new report alleges members of Trump's team were in contact with Russian intelligence officials during the year leading up to the presidential election.

The New York Times claims call records and intercepted conversations show: 'members of Donald J. Trump's 2016 presidential campaign and other Trump associates had repeated contacts with senior Russian intelligence officials in the year before the election.'

The Times said its allegations are based off interviews it has carried out with four 'current and former American officials'.

It claims US intelligence was worried because the alleged contact was taking place as then-candidate Trump continued to praise Russian President Vladimir Putin on the campaign trail.

The Kremlin said on Wednesday, however, that the report was not based on any facts.

Following his meeting with Gerasimov, Dunford will fly to Turkey on Friday for talks on a possible joint operation to recapture the Islamic State group's Syrian stronghold of Raqqa.

Turkey's defense minister Fikri Isik told reporters in Brussels that Dunford's visit to Ankara would help Washington assess whether Turkey and the United States could act jointly.

Turkey strongly objects to Syrian Kurdish fighters' participation in any operation to liberate Raqqa. It is pressing the U.S. to stop supporting Syrian Kurdish groups that Ankara considers to be 'terrorists' because of their links to outlawed Kurdish rebels in Turkey.

Isik said the impression he had from meetings with U.S. officials was that the new U.S. administration does not intend to use Syrian Kurdish forces to retake Raqqa.