Syria expects a military attack "at any moment", a security official said on Saturday, just hours after UN experts probing a suspected gas attack blamed on the regime left the country.
"We are expecting an attack at any moment. We are ready to retaliate at any moment," said the Syrian security official, who wished to remain anonymous.
The departure of the UN inspectors has opened a window for a possible US strike after President Barack Obama on Friday gave his clearest indication yet that a military intervention was imminent.
He said his administration was looking at the possibility of a "limited, narrow act", while stressing no final decision had been taken on whether to unleash military strikes against Bashar al-Assad's regime.
The UN inspectors are due to report straight back to United Nations chief Ban Ki-moon and detail their conclusions on whether a poison gas attack actually did take place on August 21, based on samples collected on site.
The Syrian regime has denied being responsible for the alleged incident -- which Washington says killed more than 1,400 people.