Andrea Mitchell asked Sen. Heidi Heitkamp (D., N.D.) why she and Sen. Joe Manchin (D., W. Va.) are willing to trust Bashar al-Assad to be forthcoming in turning over his chemical weapons to international authorities Tuesday on MSNBC.

Heidtkamp replied we are not trusting Assad, but Russia to "come to the table" on Syria:

ANDREA MITCHELL: Let me ask both of you, Senator Heitkamp, let me ask both of you, why would you trust Assad? Assad has until this initiative denied there was an attack, denied he was part of it, denied he has chemical weapons. Why on earth would we trust this man to tell us he's turned them all over to international monitoring and that he is signing a treaty that he's never [recognized]?

HEIDI HEITKAMP: We're not trusting Assad. We're trusting the Russians to come to the table.

ANDREA MITCHELL: Whoa, you're trusting the Russians?

HEIDI HEITKAMP: We're trusting Russia's intent at this point to actually deliver the right set of circumstances. I've said all along we're waiting of words are not enough. We have to see action. So it is the combination of Russia with Syria and understanding that there is this threat. That we're very serious in this country about enforcing the ban on chemical weapons one way or the other and they need to bring this country into compliance.

Not everyone in Congress shares Heitkamp's optimism in Russia's newfound willingness to convince Assad to abandon his chemical weapons.

Sen. John McCain (R., Ariz.) told CNN's Chris Cuomo the Russian proposal is worth exploring, but when you see "Russian arms flying into Damascus on a daily basis," it is "ample reason to be skeptical":

Full interview: