Pan-European air traffic control agency Eurocontrol has warned airlines to exercise caution in the eastern Mediterranean due to the possible launch of air strikes into Syria in the next 72 hours.

Eurocontrol said that air-to-ground and/or cruise missiles could be used within that period and there was a possibility of intermittent disruption of radio navigation equipment.

US President Donald Trump and Western allies are discussing possible military action to punish Syria’s President Bashar al Assad for a suspected poison gas attack on Saturday on a rebel-held town that had held out against government forces.

Trump cancelled a planned trip to Latin America later this week to focus instead on responding to the Syria incident, the White House said. Trump had on Monday warned of a quick, forceful response once responsibility for the Syria attack was established.

The Eurocontrol warning on its website did not specify the origin of any potential missile threat.

“Due to the possible launch of air strikes into Syria with air-to-ground and/or cruise missiles within the next 72 hours, and the possibility of intermittent disruption of radio navigation equipment, due consideration needs to be taken when planning flight operations in the Eastern Mediterranean/Nicosia FIR area,” it said, referring to the designated airspace.

Aviation regulators in countries including the United States, United Kingdom, France and Germany have previously issued warnings against airlines entering Syrian airspace, but the Eurocontrol statement included a broader area outside the airspace controlled by Damascus.

Eurocontrol’s warning cited a document from the European Aviation Safety Agency, Europe’s safety regulator, a copy of which was not immediately available.

Meanwhile, weapons experts will travel to the Syrian town of Douma to investigate the alleged poison gas attack.

The Syrian government has invited the Organisation for the Prohibition of Chemical Weapons to send a team to investigate allegations of a chemical attack in Douma, state media reported.

The suspected chemical weapons attack late on Saturday killed at least 60 people, with more than 1000 injured at several sites in Douma, a town near the capital, Damascus, according to the Union of Medical Care Organisations.

The Syrian medical aid group is partly funded by Western governments and operates in opposition areas.

White House spokeswoman Sarah Huckabee Sanders said in a statement on Wednesday morning (AEDT) that the President will not attend the Summit of the Americas in Lima, Peru or travel to Bogota, Colombia as planned.

Vice President Mike Pence will travel in his place. The summit is scheduled to begin on April 13.

Mr Trump said Monday he would “forcefully” respond to an alleged chemical weapons attack in Syria and would soon decide how.

France and Britain were also discussing with the Trump administration how to respond to the incident. Both also stressed that who was to blame still needed to be confirmed.

The Syrian government and its ally Russia have denied involvement in any chemical attack.

-AAP