Al-Anbar, Iraq - A rocket attack on a base in Iraq wounded seven Americans, a US official said Tuesday, with the Pentagon blaming Iran-aligned forces for the violence that comes as the region awaits an expected counterattack by Tehran on Israel.

The rocket fire the previous day was the latest in a series of attacks targeting Ain al-Assad base, which hosts American troops as well as other personnel from the US-led coalition against the Islamic State jihadist group.

"Five US service members and two US contractors were injured in the attack," in which two rockets struck the base, the US defense official said on condition of anonymity.

Five of the wounded are being treated at the base while two have been evacuated for further treatment, the official said, adding that all are in stable condition.

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President Joe Biden and Vice President Kamala Harris were briefed on the attack the previous day, the White House said.

"They discussed the steps we are taking to defend our forces and respond to any attack against our personnel in a manner and place of our choosing," it said in a statement.

A Pentagon statement on a call between Defence Secretary Lloyd Austin and his Israeli counterpart Yoav Gallant described the rocket fire as an "Iran-aligned militia attack on US forces" and said the two agreed that it "marked a dangerous escalation."

The Iraqi government's security media unit said Tuesday that the country's forces had seized a truck with eight rockets ready for launch and were pursuing the perpetrators of the attack on the military base.

It reiterated the "strong objection to any aggression, whether from inside or outside Iraq, on Iraqi territories, interests and targets."

The Monday attack on Ain al-Assad comes days after an American strike reportedly killed four pro-Iran Iraqi fighters.

"We reject all reckless actions against Iraqi bases, diplomatic missions, and locations of the international coalition advisors, as well as anything that could escalate tension in the region or drag Iraq into dangerous situations," it added.