Several Republican senators have praised President Donald Trump for showing resolve and responding to attacks by Iran-backed Iraqi militias on U.S. forces and the embassy in Baghdad.

The United States carried out five airstrikes against targets belonging to Kataib Hezbollah, a pro-Iran Iraq Shiite militia group suspected of rocket attacks on military bases in Iraq housing U.S. troops.

Members and supporters of the group gathered outside the U.S. embassy in Baghdad today and attacked the outer perimeter of the compound, prompting more warnings by Trump.

Senator Lindsey Graham of South Carolina tweeted today saying. “Very proud of @realDonaldTrump acting decisively in the face of threats to our embassy in Baghdad.”

Graham went further and, in another tweet, indirectly threatened Iran with a strike on its oil refineries.

The New York Times had reported in September that Iran’s oil refineries were among targets on the list of American military planners, in case of a conflict.

In a tweet after the embassy incident in Baghdad Trump said Iran must be held responsible for orchestrating the attack.

Senator Marco Rubio of Florida in a series of tweets backed Trump, saying, “The U.S. has shown amazing restraint responding to Iranian directed attacks. Since October we have faced 11 rockets attacks in Iraq before finally responding.” He also voiced support with the embassy staff in Baghdad and said the U.S. should employ whatever means possible to protect them.

Senator Tom Cotton of Arkansas also fired off a tweet December 31 defending the U.S. military retaliation and Trump's call for holding Iran responsible.