On Monday, a rocket attack on U.S.-led forces in northern Iraq killed a civilian contractor and wounded a U.S. service member in the worst such attack in almost a year, the U.S. coalition in Iraq said.

In and around a military airbase occupied by the U.S.-led coalition at Erbil International Airport, a missile barrage struck. The contractor who was killed was not American, two U.S. officials said. Five other contractors were injured, the coalition said, without elaborating.

The attack, alleged by an unknown group that some Iraqi officials say has ties to Iran, is raising tensions in the Middle East as Washington and Tehran are discussing a possible return to the nuclear deal with Iran.

In recent weeks, Iran-aligned militant groups in Iraq and Yemen have launched attacks against the U.S. and its Arab allies, including a drone strike at a Saudi airport and rockets against the U.S. embassy in Baghdad.

Most of the events caused no casualties, but in the early days of Joe Biden's presidency, pressure on U.S. troops and U.S. allies in the area persisted.

Biden's administration is weighing a return to the Iran nuclear agreement scrapped in 2018 by his predecessor, Donald Trump, aimed at curbing Iran's nuclear program.

U.S. allies such as France have said that any new talks should be stringent and involve Iran's biggest regional rival, Saudi Arabia. Iran insists that only if Washington lifts crippling sanctions can it return to compliance with the 2015 agreement.