WASHINGTON (AFP) - United States President Barack Obama said on Saturday he was willing to give a chance to diplomacy to help resolve the Syrian crisis, but warned the military option was still on the table.

"We need to see concrete actions to demonstrate that (Syrian President Bashar al-)Assad is serious about giving up his chemical weapons," Mr Obama said in his weekly address.

"And since this plan emerged only with a credible threat of US military action, we will maintain our military posture in the region to keep the pressure on the Assad regime."