The top diplomat of the United States has made an unannounced visit to Iraq, underlining Washington's efforts to stand up its ties with Baghdad as it pushes ahead with its "maximum pressure" against Tehran - a US arch foe but an ally of neighbouring Iraq.
Mike Pompeo on Tuesday suddenly cancelled talks in Germany and made a long detour from a European tour to spend four hours in Iraq, where he met both President Barham Salih and Prime Minister Adel Abdul-Mahdi.
"We talked to them about the importance of Iraq ensuring that it's able to adequately protect Americans in their country," the US secretary of state told reporters after the meetings. "They both provided assurances that they understood that was their responsibility," he said.
In a brief statement, Iraqi Foreign Minister Mohammed Ali al-Hakim said the talks focused on "bilateral ties, the latest security developments in the region and anti-terrorism efforts".
Pompeo said he made the trip because Iranian forces are "escalating their activity" and said the threat of attacks were "very specific".
"These were attacks that were imminent," Pompeo said.
He declined to provide additional details to back his claims, which have been met with scepticism in numerous quarters, with many fearing that President Donald Trump's administration is seeking to prompt war with Iran.
In the latest US move, the Pentagon said, it was sending several massive, nuclear-capable B-52 bombers to the region.
On Sunday, NSA John Bolton said the USS Abraham Lincoln Carrier Strike Group and a bomber task force were being deployed to the US Central Command region to send "a clear and unmistakable message" to Tehran that any attack on US interests or on its allies' will be met with "unrelenting force".
Iranian Foreign Minister Mohammad Javad Zarif said on Twitter: "If US and clients don't feel safe, it's because they're despised by the people of the region - blaming Iran won’t reverse that."
Iran's state-run Press TV earlier said: "The deployment seems to be a 'regularly scheduled' one by the US Navy, and Bolton has just tried to talk it up."
A military adviser to supreme leader Ayatollah Ali Khamenei said Washington was "neither willing nor capable" of military action against Iran, the semi-official news agency ISNA reported.
One year since US nuclear deal pullout
The rising tensions are playing out one year after the US unilaterally withdrew from the 2015 Iran nuclear deal, under which Tehran agreed to curbs on its nuclear programme in return for the lifting of international sanctions.
The Trump administration has restored US sanctions and extended them, effectively ordering countries around the world to stop buying Iranian oil or face sanctions of their own.
Iran has continued complying with the deal. Washington's European allies, which oppose the US pullout, have tried and failed to come up with ways to blunt the economic effect of Washington's move while urging Iran to continue to comply.
Iranian media reported that Tehran would write to the countries still signed up to the deal - Britain, France and Germany as well as Russia and China - on Wednesday to give them details about plans to "diminish its commitments" under the deal.
Iranian state news reports have said Iran does not plan to pull out, but will revive some nuclear activity that was halted under the deal.
"Iran's future actions will be fully within the (nuclear deal), from which the Islamic Republic will not withdraw," state media quoted Zarif as saying. "The European Union and others ... did not have the power to resist US pressure, therefore Iran ... will not carry out some voluntary commitments."