The White House declined to say whether the United States would take further military action against Syrian President Bashar al-Assad after Thursday's US strike, China's Xinhua news agency reported.

White House Press Secretary Sean Spicer told a briefing in Palm Beach, Florida, on Friday that the missile attack, the first US direct assault against the Syrian government since the Syria crisis began six years ago, was "decisive, justified and proportional."

"I think it sends a very strong signal not just to Syria but throughout the world," said Spicer, adding that the Syrian government must abide by a 2013 agreement to destroy its chemical weapons stockpile,

Syrian Foreign Minister Walid al-Moallem on Thursday denied that the chemical attack was carried out by the government, saying the incident was a result of a government airstrike on a rebel-held town in Idlib Province struck a rebel weapons depot that contained chemical materials.

The minister claimed that the Syrian army forces are no longer in possession of chemical weapons.

-- BERNAMA