The announcement comes after Syria's interim president Ahmed al-Sharaa visited the White House on Monday.
Syria will become the 90th member of the coalition, and according to a senior US official, will cooperate with the US to “eliminate what remains of ISIS.” The question of Syrian joining the cooperation was stated in advance to be one of the issues the leaders would discuss in connection with the visit.
Syria is also reportedly restoring diplomatic relations with the United States.
Monday's visit to the White House was the first by a Syrian leader since the country's independence in 1946.
