The US "strongly condemns any and all use of chemical weapons. Those responsible for the use of chemical weapons must be held accountable. We are formally requesting that the United Nations urgently investigate this new allegation," White House Principal Deputy Secretary Josh Earnest said.
Syrian rebels have accused the regime of using chemical weapons near Damascus that allegedly left more than 1,300 people dead.
However, Syria's state-run news agency Sana said, "reports on the use of chemical weapons in Ghouta are totally false. It's an attempt to prevent the UN commission of inquiry from carrying out its mission."
"If the Syrian government has nothing to hide and is truly committed to an impartial and credible investigation of chemical weapons use in Syria, it will facilitate the UN team's immediate and unfettered access to this site," Earnest said.
"We have also called for urgent consultations in the UN Security Council to discuss these allegations and to call for the Syrian government to provide immediate access to the UN investigative team," he said.
Earnest said the US is deeply concerned by reports that hundreds of Syrian civilians have been killed in the chemical weapons attack near Damascus, which he blamed on the Syrian government forces.
"We are working urgently to gather additional information," he said.
