BAGHDAD (AP) — The Trump administration has warned Iraq that it will close its embassy in Baghdad if the government does not take swift and decisive action to end persistent rocket and other attacks by Iranian-backed militias and rogue armed elements on American and allied interests in the country, U.S., Iraqi and other officials said Monday.

As news of the warning sent shockwaves across Baghdad, Iraq’s military said a Katyusha rocket hit near Baghdad airport, killing five Iraqi civilians and severely wounding two others.

A U.S. official said the administration’s warning was given to both Iraq’s president and prime minister but that it was not an imminent ultimatum. The official was not authorized to discuss the matter publicly and spoke on condition of anonymity.

The warning signals the administration’s increasing frustration and anger with ongoing rocket fire from Iranian-supported groups on or near the vast U.S. Embassy compound in Baghdad as it steps up pressure on Iran with the re-imposition of crippling sanctions. However, closing the embassy and withdrawing U.S. personnel from Baghdad would signal a significant retreat from a country in which successive administrations have invested massive amounts of money and lives.

The threat to evacuate the embassy, which has stoked concerns in Baghdad of a diplomatic crisis, was first delivered to President Barham Saleh on Tuesday in a phone call with U.S. Secretary of State Mike Pompeo, Iraqi officials said. Pompeo then repeated the warning to Iraqi Prime Minister Mustafa al-Kadhimi on Saturday, the officials said.

Pompeo told Saleh that if the U.S. presence continues to be targeted, measures would be taken to close the embassy and a “strong and violent” response would follow against the groups responsible for the attacks, according to three Iraqi officials with knowledge of the call.

Pompeo went further with al-Kadhimi on Saturday, telling the prime minister that the U.S. will initiate plans to withdraw from the embassy, according to the Iraqi officials who spoke on condition of anonymity in line with regulations.

An official announcement has not been made by the Americans. But the Trump administration has not been shy about expressing its anger and concern about continuing rocket attacks by Iranian-backed groups on or near the embassy compound.

In a tangible sign of a strain in U.S.-Iraq relations, the State Department shortened an Iran sanctions waiver deadline by 60 days last week. The previous waiver, crucial for Iraq to import badly needed Iranian gas to meet power demands, gave the government 120 days.

Without the waiver, Iraq would suffer crippling sanctions barring it access to U.S. dollars.

Despite comments from U.S. officials that a deadline on closing the embassy is not in place, Iraqi officials appeared to be under the impression they have until the waiver expires in two months’ time to take action.