The U.S. is sending additional troops to Baghdad to safeguard its personnel amid protests against Washington's airstrikes last weekend.

Secretary of Defense Mark Esper said the Pentagon is working closely with the State Department to ensure the security of its embassy and personnel but he did not elaborate on the number or timing of the announced deployment.

"We have taken appropriate force protection actions to ensure the safety of American citizens, military personnel and diplomats in country, and to ensure our right of self-defense. We are sending additional forces to support our personnel at the Embassy," said Esper.

Esper urged the Iraqi government fulfill its responsibilities to assist in the protection of the U.S. personnel, saying Washington "continues to support the Iraqi people and a free, sovereign, and prosperous Iraq."

Thousands of outraged Iraqi protesters stormed the U.S. embassy compound Tuesday, protesting Washington's airstrikes Sunday on five Kataib Hezbollah targets in Iraq and Syria that killed at least 25 Iranian-backed Hashd al-Shaabi fighters.

That airstrikes were in response to a rocket attack Friday on a U.S. military base in Kirkuk, blamed on the Kataib Hezbollah, which is part of the Hashd al-Shaabi group, or Popular Mobilization Forces.

Friday's attack killed one U.S. contractor and wounded four U.S. service members.

Iraqi Prime Minister Adil Abdul-Mahdi said Baghdad condemns the airstrikes on Iraqi military elements and warned those taking part in funeral marches to stay away from foreign buildings and compounds.

"Iraqi security forces will respond to any act of aggression or harassment against foreign embassies in Iraq, and those responsible will face the full force of the law," Abdul-Mahdi said on Twitter.