WASHINGTON - US President Donald Trump will skip his first Latin America trip to stay in the United States to "oversee the American response to Syria," the White House said on Tuesday.

Trump was scheduled to pay a visit to Peru and Colombia this week, during which he would attend the Summit of the Americas in the Peruvian capital city of Lima.

US Vice President Mike Pence will travel to the region instead, according to a White House statement.

Trump has been mulling response to the alleged "chemical attack" that occurred in Syria on Saturday, with the possibility of US military actions against Syria looming large.

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

"It (the attack) will be met forcefully," he added.

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

The Syrian Foreign Ministry denied the accusations, saying the rebels' claims were "premeditated pretexts," according to the country's state-run news agency SANA.