Rep. Alexandria Ocasio-Cortez (D-N.Y.) accused President Trump of an "act of war" following the Thursday airstrike in Iraq he ordered that killed Iranian Maj. Gen. Qassem Soleimani.

"Last night the President engaged in what is widely being recognized as an act of war against Iran, one that now risks the lives of millions of innocent people," Ocasio-Cortez tweeted Friday.

The drone strike followed an assault on the U.S. Embassy in Baghdad on Tuesday by supporters of an Iranian-backed militia, which itself followed reciprocal airstrikes by both sides over the weekend.

Secretary of State Mike Pompeo has said that "de-escalation" is the goal of the U.S. and said the attack was carried out because of "imminent threats to American lives."

Democrats, however, described the action as a "massive escalation" and said it could provoke "further dangerous escalation of violence."

Iran has warned of "harsh retaliation" following the strike.

Meanwhile, the Pentagon said Friday that about 3,000 U.S. troops will be deployed to the Middle East as tensions rise.