Deputy National Security Advisor: Obama will outline 'compelling' case on Assad Tuesday

When President Barack Obama addresses the nation Tuesday night, he will provide more information linking Syrian President Bashar al-Assad to the use of chemical weapons.

"He'll be able to lay out in a very compelling way exactly what we know, and he'll be able to give you some idea of how we know it," said Deputy National Security Advisor Antony Blinken.

Assad said in an interview with CBS's Charlie Rose Monday that the U.S. does not have the evidence, a statement Blinken refutes.

"The president will have an opportunity tomorrow night to lay out the case that we're making and we've been doing that in a classified setting with members of Congress. ... When they read it, when they see it, when they're able to ask questions on it, they come away convinced," said Blinken.

Obama is addressing the nation in an attempt to garner support for U.S. intervention in Syria. But Secretary of State John Kerry, off-the-cuff, proposed a hypothetical situation Monday, saying if Assad were to surrender his chemical weapons to the international community, he may avoid a military strike.

"The only reason this is even being discussed is because of the pressure we're exerting, and the threat of the use of force," said Blinken.

If Congress authorizes U.S. intervention in Syria, it "would actually enhance any options that may exist for some kind of resolution, but absent that authority, it's going to make it tougher," added Blinken.

For more of our interview with Antony Blinken, including more on how Obama will convince Americans to support a strike in Syria, check out the video above.