UN Secretary-General Antonio Guterres on Friday urged restraint and the search for a political solution in Syria a day after the United States struck an air base in the country in retaliation for a chemical attack.

"Mindful of the risk of escalation, I appeal for restraint to avoid any acts that could deepen the suffering of the Syrian people," he said in a statement. "There is no other way to solve the conflict than through a political solution."