1 of 4 | Members of Iraqi Shiite 'Popular Mobilization Forces' armed group and their supporters attack the entrance of the U.S. Embassy, in Baghdad, Iraq, on Tuesday. Photo by Humam Mohamed /UPI | License Photo
Dec. 31 (UPI) -- President Donald Trump on Tuesday said Iran will face consequences after protesters attacked the U.S. Embassy in the Iraqi capital of Baghdad.
Trump blamed the protests on Iran in a Twitter post, saying it was "orchestrating" them and calling on Iraq to "use its forces" to protect the embassy.
"Iran will be held fully responsible for lives lost, or damage incurred at any of our facilities," Trump wrote on Twitter. "They will pay a very BIG PRICE! This is not a Warning, it is a Threat."
An embassy spokesman told CNN the embassy personnel were secure following an assault by hundreds of protesters who were angered by a series of deadly American airstrikes carried out Sunday against an Iranian-backed Iraqi militia group in Iraq and Syria.
Protesters entered the heavily fortified "Green Zone" near the compound after apparently being granted access by Iraqi security forces and gathered at the walls of the embassy itself to denounce the U.S. airstrikes against the Kata'ib Hezbollah militia.
Iraqi counterterrorism forces were deployed to the area and the Pentagon announced additional Marines would be sent to Baghdad in response to the attack.
Secretary of Defense Mark Esper said that he will be immediately deploying about 750 additional troops to the Middle East in response to the attack.
He said in a statement that Trump had authorized him to deploy an infantry battalion from the Immediate Response Force of the 82nd Airborne Divison.
"This deployment is an appropriate and precautionary action taken in response to increased threat levels against U.S. personnel and facilities, such as we witnessed in Baghdad today," he said. "The United States will protect our people and interests anywhere they are found around the world."
In a separate statement, he said the Department of Defense was working closely with the State Department to ensure the security of the embassy and its personnel in Baghdad and that they 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."
U.S. officials blamed the militia for the death of a U.S. contractor in Kirkuk, Iraq, late last week.
Social media posts showed protesters breaking the embassy's windows and setting fires outside its walls in a violent display of anger.
Caretaker Iraqi Prime Minister Adil Abdul-Mahdi urged the protesters to leave, saying any aggression against the embassy is "strictly prohibited by the security forces and will be punished by law with the most severe penalties."
Reports indicated Iraqi security forces used "non-lethal means" to eventually push the protesters back while U.S. Marines arrived from Kuwait and two Apache helicopters fired flares while conducting a flyover of the embassy in a show of force.
As night fell, the protesters said they would attempt to pitch tents as part of an open-ended sit-in, calling on the Iraqi parliament to end U.S. presence and intervention in the country.
Kata'ib Hezbollah is part of a group of mainly Shiite militias backed by Iran and sanctioned by Baghdad called the Iraqi Popular Mobilization Units. The PMU said the airstrikes on five sites in western Iraq and eastern Syria killed at least 25 people and wounded 51.
The U.S. actions were criticized by Iraqi and Iranian officials Monday as a dangerous escalation of a volatile situation in Iraq, which has been convulsed by months of mass protests over living conditions and political corruption.
Iraqi President Barham Salih on Monday called the U.S. airstrikes "unacceptable" and considered them "an aggressive action and violation of Iraqi sovereignty."
Abdul-Mahdi released a statement saying he urged U.S. Defense Secretary Mark Esper not to carry out the strikes shortly before they were launched.
"Bombing PMU bases is a dangerous aggravation which endangers the security of Iraq and the region," he said.