The US may consider a military response to Wednesday’s rocket attacks on its troops in Iraq after a US contractor died as a result of the incident, the White House and the military said.
At least 10 rockets hit Al Asad airbase in western Iraq's Anbar province housing US and coalition troops fighting ISIS.
"We are following that through right now," President Joe Biden said. "Thank God, no one was killed by the rocket, but one individual, a contractor, died of a heart attack. But we're identifying who's responsible and we'll make judgments [about a response]."
White House press secretary Jen Psaki suggested that calculated US air strikes last week could be a model for a military response. Those strikes were in response to an attack on American forces in northern Iraq earlier in February.
“If we assess further response is warranted, we will take action again in a manner and time of our choosing,” Ms Psaki said. "What we won't do is make a hasty or ill-informed decision that further escalates the decision or plays into the hands of our adversaries."
The Pentagon said on Wednesday that the US had shown it would not “shy away” from taking action on such attacks.
"Let's do this the right way. Let's let our Iraqi partners investigate this, see what they learnt," Pentagon spokesman John Kirby said, calling the attack a "troubling development".
"And then, if a response is warranted, I think we have shown clearly that we won't shy away from that. But we're just not there yet," Mr Kirby said, declining to speculate about whether a response was likely.
While it is unclear exactly who was behind the attack, Iraqi forces found the launch site several kilometres from the airbase where there were a number of burning vehicles that were used in the attack.
The Pentagon said the rockets appeared to have been fired from sites east of the Iraqi base, which was targeted last year by a ballistic missile attack directly from Iran.
It said it was too soon to come to any conclusions on which group was responsible for the attack – no one has yet claimed responsibility – but Mr Kirby said the attack was "similar to recent attacks by Shiite-backed militias".
"We cannot attribute responsibility at this time, and we do not have a complete picture of the extent of the damage," Mr Kirby said.
Iraqi forces continue to investigate the attack and US forces are on standby to assist, Mr Kirby said.
Sky News Arabia reported that Iraqi soldiers were brought in for questioning after surveillance footage of a checkpoint showed the suspect vehicles that may have been carrying the rockets passing through without inspection.
Prime Minister Mustafa Al Kadhimi said that his administration had been negotiating with the US and allies on the future of foreign forces in Iraq and there had been reductions, but such attacks were never justified and were detrimental to the process of talks.
Iran-backed militia groups have long demanded that US forces leave Iraq and their allies in parliament last year passed a bill ordering the withdrawal.
Last Thursday, US forces carried out air strikes against facilities at a border control point in Syria used by Iranian-backed militias, including Kataib Hezbollah and Kataib Sayyid Al Shuhada.
Despite a deterioration in security in some parts of the country, Pope Francis is expected to begin a four-day visit to Iraq on Friday.