Iran has condemned the US retaliatory airstrikes targeting the bases of Iran-backed militants in Iraq and Syria. Iraq and Syria have also criticized the attacks, which reportedly killed at least 45 people.

The US Central Command said its forces launched airstrikes targeting Iran's Islamic Revolutionary Guard Corps Quds Force and affiliated militia groups on Friday.

White House National Security Council spokesperson John Kirby had told reporters last Sunday that the US would retaliate for the deaths of three US soldiers in a drone strike in Jordan.

US forces on Friday hit 85 targets at seven locations in Iraq and Syria, including command and control headquarters, missiles, drone storage sites and other facilities related to the Quds Force or militias.

Kirby said the US action would not be just one hit but a tiered response over time. But he also said, "We do not seek another war. We do not seek to escalate."

Iran's foreign ministry spokesperson said in a statement on Saturday that the US attacks were violations of the sovereignty and territorial integrity of Iraq and Syria. He also said the US government has made another strategic mistake.

The UK-based Syrian Observatory for Human Rights reported that 26 locations were targeted and 18 militants were killed in the Syria strikes.

Syrian state media carried a statement by the military that said the US strikes cannot be justified.

In Iraq, a government spokesperson said 16 people were killed, including civilians. Twenty-nine people were reportedly injured.

The statement said the US action pushes the security situation in Iraq and the region "to the brink of the abyss," and jeopardizes ongoing efforts to create stability.