In a letter sent to Congress, US President Donald Trump says the United States "will take additional action, as necessary and appropriate."
US President Donald Trump on Saturday warned of taking further actions "as necessary" in Syria two days after US missile strikes in the war-torn country.
In a letter addressed to House Speaker Paul Ryan and Senate president pro tempore Orrin Hatch, Trump gave details on the missile strike on the Shayrat military air field.
US warships in the Mediterranean fired 59 Tomahawk cruise missiles at about 3:40am Syria time (late Thursday in Washington, 0040 GMT Friday) at the air base located near Homs in central Syria.
Degrading Syrian regime's ability
US intelligence indicated that "Syrian military forces operating from this air field were responsible for the chemical weapons attack on Syrian civilians in southern Idlib Province, Syria, that occurred on April 4," Trump wrote.
Trump wrote that he "acted in the vital national security and foreign policy interests of the United States, pursuant to my constitutional authority to conduct foreign relations and as commander in chief and chief executive.
He then added that the United States "will take additional action, as necessary and appropriate, to further its important national interests."
Trump said that he was writing to keep Congress informed "consistent with the War Powers Resolution," a 1973 measure mandating the president to notify Congress of military action.
The Tomahawks targeted aircraft, hardened aircraft shelters, petroleum and logistical storage, ammunition supply bunkers, air defence systems and radars, the Pentagon said.