WASHINGTON, April 10 (Xinhua) -- U.S. Defense Secretary James Mattis has canceled his weekend trip to California over the upcoming U.S. response to the alleged chemical weapons attack in Syria, local media reported Tuesday.

The trip was canceled following President Donald Trump skipping his first trip to Latin America scheduled for the weekend to oversee "the American response to Syria".

Trump has been mulling a response to the alleged "chemical attack" on Saturday, with the possibility of U.S. military actions against the Syrian government looming large.

Mattis, who planned to visit California and Nevada, is expected to attend a White House meeting on Wednesday for further discussions on Syria, local media reported.

On Monday evening, Trump said the United States is "going to make a decision tonight or shortly thereafter" on the Syria incident.

Activists, local rescuers and rebels in Syria claim that Syrian government forces used chlorine gas on Saturday in an attack in Douma, a rebel-held area near capital Damascus.

The Syrian Foreign Ministry has denied the accusations, calling rebels' claims "premeditated pretexts".