Syria's Assad says US has no proof of chemical weapons use

Syrian President Bashar al-Assad has told a US broadcaster there is "no evidence" that his government has used chemical weapons.

In the interview with PBS, to be aired on Monday, he also suggested his allies would retaliate if the West attacked.

US Secretary of State John Kerry has been lobbying hard for military action against Mr Assad during talks with EU and Arab foreign ministers in Europe.

Congress is due to debate whether to authorise intervention in Syria.

Lawmakers will return from their summer recess on Monday to start discussing President Barack Obama's resolution to launch a "limited, narrow" strike.

A Senate vote on the issue is expected as early as Wednesday, although the timetable for Mr Obama's request is less certain in the House, where the measure faces an even rockier time.

The US accuses Mr Assad's forces of killing 1,429 people in a sarin gas attack on 21 August on the outskirts of the capital, Damascus.

Mr Assad's government blames the attack on rebels fighting to overthrow him in the country's two-and-a-half-year civil war, which has claimed some 100,000 lives, according to UN estimates.