President Vladimir Putin warned Washington that Russia was not 'a fire brigade' and could not 'rescue everything' as tension rise between the US and Iran.

Tensions have sharply escalated between arch-rivals Washington and Tehran since US President Donald Trump withdrew last year from the Iran nuclear deal which removed sanctions in exchange for curbs on Iran's nuclear programme.

Putin spoke to reporters after hosting US Secretary of State Mike Pompeo in the Black Sea resort of Sochi on Tuesday for the highest-level bilateral talks in nearly a year.

Russian president Vladimir Putin, pictured, said Moscow would not be able to act as 'a fireman' to settle a dispute between the United States and Iran over Tehran's nuclear deal

Mr Putin met with US Secretary of State Mike Pompeo, left, on Tuesday in Sochi, Russia

Tensions are increasing in the Gulf after the MV Al Marzoqah oil tanker under Saudi Arabian flag was attacked on May 12, 2019 outside Fujairah port in the United Arab Emirates

'We regret that the deal is falling apart,' Putin said following talks with Austrian President Alexander van der Bellen on Wednesday.

'After the signing of the agreement Iran was and still is the world's most verifiable and transparent country in this sense.'

'Iran is fulfilling all of its obligations,' said Putin, citing the International Atomic Energy Agency.

He urged Iran not to quit the 2015 agreement but added there was only so much Moscow could do.

'Russia is not a fire brigade,' Putin said.

'We cannot rescue everything that does not fully depend on us. We've played our part.'

Putin also said that after Washington's withdrawal Europe could do 'nothing' to salvage the deal.

Earlier Wednesday Putin's spokesman Dmitry Peskov expressed concern that tensions over Iran escalated despite assurances from Pompeo that Washington was not seeking war.

President Donald Trump has warned he has naval assets in the region, such as the USS Abraham Lincoln, pictured here being replenished at sea by the support ship USNS Arctic

'So far we notice the continued escalation of tensions around this subject,' Peskov said.

'We are saddened to see the decisions taken by the Iranian side,' Peskov added, while arguing that Washington has been provoking Iran.

In Sochi, Pompeo said his country did not want war with Iran, despite a spike in tensions that has seen the Pentagon dispatch nuclear-capable bombers to the region.

Peskov sought to play down those statements.

'There were no assurances from Pompeo,' Putin's spokesman said.

'And one can hardly talk about some sort of assurances.'

Washington last year pulled out of a nuclear deal backed by Europe, Russia and China, which curbed Iran's nuclear ambitions in return for sanctions relief.

Since then it has slapped sweeping sanctions on Iran.

On Sunday, mysterious attacks by unknown assailants against four ships in the region, including two from Saudi Arabia, pushed talk of war up another notch.

The Andrea Victory, pictured, was holed before the waterline as a result of the attack

Washington has accused Iran of planning 'imminent' attacks in the region and on Wednesday, the US ordered all non-emergency staff to leave its embassy in the Iraqi capital Baghdad and consulate in Arbil.

The US on Wednesday ordered all non-emergency staff to leave its embassy in Baghdad and consulate in Arbil, ramping up alarm over an alleged Iran threat even as allies appeared less than convinced.

A senior Democratic senator demanded President Donald Trump's administration brief Congress on the Iran threat, warning that the US legislature has not approved military action against Tehran.

And Moscow expressed concerns that both Washington and Tehran were dangerously stoking tensions, as the Pentagon ramped up its forces in the Gulf with B-52 bombers, Patriot missiles and an aircraft carrier task force.

The embassy evacuation came 10 days after Trump's national security advisor John Bolton announced the military deployment in response to intelligence on an unspecified 'imminent' plot by Iran to attack US forces or allies.

The State Department warned Wednesday of numerous 'terrorist and insurgent groups' active in the country, including 'anti-US sectarian militias' who could 'threaten US citizens and Western companies throughout Iraq.'

The Norwegian-flagged vessel was one of those damaged in the sabotage attack

The warning did not mention Iran specifically, but 'anti-US sectarian militias' points to Iran-backed groups.

A State Department spokesman told AFP the departure of non-emergency personnel came in response to 'the increased threat stream we are seeing in Iraq.'

Washington says it has received intelligence on possible attacks by Iranian or Iranian-backed forces, possibly targeting US bases in Iraq or Syria.

Some observers speculate that Tehran is seeking to retaliate to Washington's decision in April to designate the Islamic Revolutionary Guard Corps of Iran as a terrorist organisation in an effort to stymie their activities across the Middle East.

But since the first US warning on May 5, the only activity seen has been a still-mysterious 'attack' Monday on four tankers anchored off Fujairah, a UAE port at the strategically crucial entrance to the Gulf.

One or more vessels incurred light hull damage, but what caused the damage and who was behind it remains unknown.

US allies in Iraq have refrained from echoing Washington's warning cry.

Major General Chris Ghika, a British spokesman for Operation Inherent Resolve, the coalition fighting ISIS, said Tuesday there was no special heightened alert, and that OIR troops were always on guard against possible attacks.

After Ghika's comments drew a sharp retort from the US Central Command, Britain's defense ministry said Wednesday they have 'long been clear about our concerns over Iran's destabilising behavior in the region' - while still not confirming any new imminent danger.

Germany and the Netherlands said Wednesday they were suspending training of soldiers in Iraq; German defence ministry spokesman Jens Flosdorff said there was 'generally heightened alert, awareness' among soldiers in the region, but gave no specifics.

Separately, the Netherlands' defense ministry said it was suspending a training mission in Iraq due to 'threats,' according to the Dutch ANP news agency.

In the US Congress Democrats demanded to know why the Trump administration was boosting its forces in the Gulf and, according to media reports, considering military plans including the possibility of sending 120,000 US troops to the Middle East if Iran attacks American assets.

'The Trump administration has not provided any information to this committee on the intelligence behind their decisions, or what they plan to do in Iraq or Iran,' said Senator Bob Menendez, the senior Democrat on the Senate Foreign Relations panel.

He demanded a briefing 'immediately' on the threat intelligence, any plans for war and the decision to order embassy staff out of Iraq.

'Congress has not authorized war with Iran... If (the administration) were contemplating military action with Iran, it must come to Congress to seek approval,' he said.

The United States believes Iranian proxies were involved in the attacks on two Saudi registered oil tankers off the United Arab Emirates.

The UAE had said on Sunday that four commercial vessels were attacked near Fujairah, one of the world's largest bunkering hubs. The port lies near the Strait of Hormuz, one of the world's most important oil export waterways.

Iran's foreign ministry described the incidents as "worrisome and dreadful" and called for an investigation.

Saudi Arabia and the UAE are the largest and third-largest producers respectively in the Organization of the Petroleum Exporting Countries (OPEC).