Enraged by near-daily attacks on its interests in Iraq, Washington has threatened to close its embassy in Baghdad, in a blow to a premier seen as a bulwark against Iran. The ultimatum was delivered in recent phone calls by U.S. Secretary of State Mike Pompeo to President Barham Salih and Prime Minister Mustafa al-Kadhimi.

The two Iraqi officials also said the U.S. has begun taking preliminary steps to close the embassy in the next few months, that the closure may occur simultaneously with the withdrawal of American troops from Iraq and that the Consulate General in Erbil will be kept open.

Militant groups have been frequently launching mortar attacks against Iraqi military bases housing U.S. troops and the U.S. embassy in Baghdad's heavily fortified Green Zone, where some foreign embassies are also located.

Iraq has long been caught in a tug-of-war between its allies Iran and the U.S., rendered rockier by Washington's "maximum pressure" policy against Tehran since 2018.

The U.S. still has hundreds of diplomats in its mission at the high-security Green Zone in Baghdad and around 3,000 troops based in three bases across the country. Since 2019, dozens of rockets and improvised explosives have targeted these sites, with U.S. and Iraqi officials blaming Tehran-backed factions including Kataib Hezbollah.

Washington has twice retaliated with strikes on Kataib Hezbollah in Iraq and threatened earlier this year to bomb more than 120 further sites if the rocket attacks cost American lives, a top Iraqi official told AFP.

The frustration failed to ease even after Mustafa al-Kadhemi, seen as Western-leaning, took office as premier in May. Ahead of Kadhemi's visit to Washington in August, the U.S. signaled it was "unsatisfied with his actions" against pro-Iran armed groups, an Iraqi official said.

Fresh in the minds of Iraqi officials and armed groups is the U.S. drone strike in January that killed top Iranian Gen. Qassem Soleimani and Abu Mahdi al-Muhandis, the deputy head of Iraq's state-sponsored Hashed al-Shaabi (Popular Mobilization Forces). Since then, many pro-Iran paramilitary leaders have gone into hiding lest they be subject to American strikes or sanctions.

The new U.S. threats seem to have deepened the growing rift between factions loyal to Iran and those less willing to enter into a full confrontation with the U.S. After months of silence, Muqtada al-Sadr, head of the Saeroon bloc, took to Twitter this week to call for "the creation of a security, military and parliamentary committee to investigate" the rocket attacks. Within minutes, Kadhemi and other top government figures endorsed the recommendation.

"There's a consensus on condemning these attacks. Kataib Hezbollah and other hardliners are isolated and left without political cover," an Iraqi official said.

Even the Hashed al-Shaabi slammed rocket attacks as "illegal military acts", denied involvement and formally sidelined a pair of commanders seen as too Tehran-leaning. But the hardliners, too, are organizing. A half-dozen previously unheard-of groups have claimed responsibility for rocket attacks on the U.S. and even threatened the United Nations in recent months. Iraqi intelligence officials and political sources say Iran has been gathering the most hardline among its Iraqi allies into these new formations.