Asked about Allawi's statement, a State Department spokesperson said that "we do not comment on alleged intelligence reports", but added: "The threats that led us to take precautions in Iraq are directly linked to Iran". "The U.S. government has limited ability to provide emergency services to U.S. citizens in Iraq".
On May 5, Trump's hawkish National Security Advisor John Bolton announced the deployment of the USS Abraham Lincoln aircraft carrier strike group and a B-52 bomber force to the Gulf.
On a visit to Tokyo, Mohammad Zarif defended Iran's right to respond to the U.S. pullout from the nuclear deal a year ago and ensuing imposition of sanctions by the Trump administration.
On Tuesday, Iran's Ayatollah, Seyed Ali Khamenei, said that any confrontation between the United States and Iran would not be "a military one", and that "there was not going to be any war".
Trump quit the Iran nuclear deal in May 2018 and gradually reimposed sanctions on the country.
The official also said the ultimate goal of the yearlong economic sanctions campaign by the Trump administration was to draw Iran into an armed conflict with the United States.
Washington officials said they had detected signs of Iranian preparations for potential attacks on U.S. forces and interests in the Middle East have not elaborated on that threat.
According to a BBC Arabic report, Pompeo handed over a memory stick to Iraqi Prime Minister Adil Abdul Mahdi containing evidence of Iran's plans to attack USA interests in Iraq through its proxies in the country.
Iraq's status as an area of shared influence between Iran and the United States leaves the country's leaders with few options.
No specific details on the threat have been released, but claims of a rising threat of asymmetric warfare against soft targets are reported.
Britain appears to have drawn similar conclusions to the US amid the increasing tensions between the Trump administration and the Iranian regime, even though a British general took an unusual step to disregard the Iranian threat on Monday.
His remarks were at odds with the United States administration's claims that Iranian-linked groups were preparing to attacks western targets in the region and prompted a rare public rebuke from the Pentagon.
Britain's Major General Chris Ghika, a spokesman for Operation Inherent Resolve, the coalition fighting the jihadist Islamic State group, said Tuesday there was no special heightened alert.
Khamenei told Iranian officials the standoff "is not military because there is not going to be any war".
Now that the next wave of a proxy war is mounting, these Iraqi factions might once again rise as an Iranian tool to confront U.S. pressure.