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.