US President Joe Biden on Tuesday called Iraqi Prime Minister Mustafa Al Kadhimi, Baghdad announced.
The call is the first from Mr Biden to an Arab leader since he became president and the second to the Middle East, after Israel.
It comes eight days after a rocket attack in Erbil in northern Iraq, which killed a military contractor and wounded US service members.
In its readout, White House said the two leaders agreed that those responsible for the attacks should be “held fully to account.”
"They discussed the recent rocket attacks against Iraqi and Coalition personnel and agreed that those responsible for such attacks must be held fully to account," according to the statement.
Mr Biden "affirmed U.S. support for Iraq's sovereignty and independence and commended the Prime Minister's leadership…they discussed the importance of advancing the Strategic Dialogue between our countries and expanding bilateral cooperation on other key issues," the White House said
Mr Al Kadhimi announced in a tweet on Tuesday that he had spoken with Mr Biden and reaffirmed security and bilateral commitments.
“We reaffirmed our commitment to bolstering Iraqi-US ties for the benefit of our peoples and co-operation in fighting [ISIS] to ensure regional peace and stability,” he said.
Mr Kadhimi’s office said in a statement that during the call, the two sides “emphasised the importance of protecting diplomatic missions in Iraq and rejecting attempts to destabilise Iraq and the region".
Rocket attacks on the US embassy in Baghdad have escalated in the past three months. On Monday, Katyusha rockets landed inside the Green Zone, US and Iraqi officials said.
A diplomatic source told The National that Mr Biden and Mr Al Kadhimi discussed the Erbil attack during the call.
The Biden administration said it was assisting Iraq in an investigation into the attack and would make a response at the appropriate time.
“We will respond in a way that’s calculated within our own timetable and using a mix of tools at a time and place of our choosing,” US spokesman Ned Price said on Monday.
“What we will not do is lash out and risk an escalation that plays into the hands of Iran and contributes to their attempts to further destabilise Iraq.”
Mr Price did not directly blame Tehran’s proxies in Iraq for the attack but said rockets used in similar attacks were made in Iran.
“We know that many of these attacks have used Iranian-made, Iranian-supplied weapons, but this is something that remains under active investigation," he said.
A diplomatic source told The National that the Erbil attack was discussed during the call between Mr Biden and Mr Al Kadhimi.
Issues related to counter-terrorism and furthering the strategic dialogue between US and Iraq were also discussed.
The call to was the first made by the US president to an Arab leader.
On January 28, US Secretary of State Antony Blinken also gave Iraq’s Foreign Minister Fuad Hussein the courtesy of the first call to an Arab peer.