WASHINGTON: US President Donald Trump said on Thursday he ordered missile strikes against a Syrian airfield from which a deadly chemical weapons attack was launched, declaring he acted in America’s “vital national security interest” against Syrian President Bashar al-Assad. Sharply escalating the US military role in Syria, two US warships fired dozens of cruise missiles from the eastern Mediterranean Sea against the airbase controlled by Assad’s forces in response to the poison gas attack on Tuesday in a rebel-held area, US officials said. Facing his biggest foreign policy crisis since taking office in January, Trump took the toughest direct US action yet in Syria’s six-year-old civil war, raising the risk of confrontation with Russia and Iran, Assad’s two main military backers. US officials insisted they informed Russian forces ahead of the missile attacks and that there were no strikes on sections of the base where Russians were present. But they said the administration did not seek Moscow’s approval.