Syrian President Bashar al-Assad tells PBS there is “no evidence” that his government has used chemical weapons.
He also suggested that Syrian 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 authorize 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.
“The next few days will see Mr Obama stripped, all the flaws of his presidency on display, all the strengths of his personality strained to their limit”
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.
UK Foreign Secretary William Hague cautioned against believing what al-Assad said.
“We mustn’t fall into the trap of attaching too much credibility to the words of a leader – President Assad – who has presided over so many war crimes and crimes against humanity,” Mr Hague said.
The White House has admitted it has no “irrefutable” evidence of Mr Assad’s involvement in the August attack, but said a “strong common-sense test irrespective of the intelligence” suggested his government was responsible.
“We’ve seen the video proof of the outcome of those attacks,” White House Chief of Staff Dennis McDonough said on Sunday.
“Now do we have a picture or do we have irrefutable beyond-a-reasonable-doubt evidence? This is not a court of law and intelligence does not work that way.”
Today’s Question: Do you believe Syrian President Bashar al-Assad that his government had no role in chemical attacks?