US Secretary of State Mike Pompeo on Friday (December 13th) warned Iran of a "decisive" response if US interests are harmed in Iraq, after a series of rocket attacks on bases.
"We must... use this opportunity to remind Iran's leaders that any attacks by them, or their proxies of any identity, that harm Americans, our allies or our interests will be answered with a decisive US response," Pompeo said in a statement.
"Iran must respect the sovereignty of its neighbours and immediately cease its provision of lethal aid and support to third parties in Iraq and throughout the region," he said.
The US has expressed mounting concern about the flurry of attacks on Iraqi bases used by US troops, several of which it has blamed on Iran-backed factions in Iraq.
Two rocket attacks last week targeted a compound near Baghdad International Airport, which houses US troops, with an incident Monday wounding Iraqi troops.
Pompeo, who has repeatedly warned Tehran, pinned the blame for the latest attacks squarely on "Iran's proxies".
Iraq warns against 'escalation'
On Monday (December 16th), US defence secretary Mark Esper "expressed his concern" over the strikes in a telephone call with outgoing prime minister Adel Abdul Mahdi, according to a statement from the premier's office.
In response, Abdul Mahdi "called on everyone to spare no effort to prevent an escalation that will threaten all parties", the statement added.
"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.
"If the Iraqi government or state weakens, this will exacerbate escalation and chaos," Abdul Mahdi told Esper, according to the statement.
The US has recently reinforced its security at its embassy in Baghdad's ultra-secure Green Zone, according to an Iraqi security source, who said "a convoy of 15 American vehicles each transporting armoured trucks and weapons entered the Green Zone".
The US has been trying to counter Tehran's influence around the region, including through sanctions aimed at blocking all its oil exports.
Last week, it imposed sanctions on three leaders of Iran-backed militias within the Popular Mobilisation Forces, accusing them of taking part in the deadly crackdown on nationwide protests.