The US has called on Baghdad to "take proactive actions" to protect US interests in the country after a flurry of attacks that have been blamed on Iran-backed groups.
Since October 28th, 10 rocket attacks have targeted areas where US soldiers and diplomats are stationed. They have not been claimed, but the US has blamed Iran-backed Iraqi paramilitary groups.
US Defense Secretary Mark Esper told reporters Monday (December 16th) he had expressed "concern about the optics in attacks on bases in Iraq where US troops and materiel might be", in a call with outgoing prime minister Adel Abdul Mahdi.
The US has "a right of self defense, that we would ask our Iraqi partners to take proactive actions... to get that under control, because it is not good for anybody", he told Abdul Mahdi.
Abdul Mahdi's office released a statement earlier Monday confirming the phone call and asking everyone "to spare no effort to prevent an escalation that will threaten all parties".
"Unilateral decisions will trigger negative reactions that will make it more difficult to control the situation and will threaten Iraq's security, sovereignty and independence," he said.
Esper, speaking on a plane returning from Belgium, where he had attended the 75th anniversary of the Battle of the Bulge, acknowledged Tehran's involvement was difficult to prove.
"My suspicion would be that Iran is behind these attacks, much like they are behind a lot of malign behaviour throughout the region," he said. "But it is hard to pin down."
Abdul Mahdi resigned in early December after two months of unprecedented demonstrations in the capital and south Iraq that have left 460 people dead. Negotiations are underway to name his successor.
"If the Iraqi government or state weakens, this will exacerbate escalation and chaos," Abdul Mahdi told Esper, according to the statement.
A US source recently told AFP that pro-Iran factions in Iraq were now considered a more significant threat to American soldiers than the "Islamic State of Iraq and Syria" (ISIS).
The attacks have killed one Iraqi soldier and left others wounded, as well as causing material damage in the vicinity of the US embassy in Baghdad's ultra-secure Green Zone.
The US has recently reinforced its security at the embassy, according to an Iraqi security source, who said "a convoy of 15 American vehicles each transporting armoured trucks and weapons entered the Green Zone".