“I’d be hard pressed to make the case to you that he should have a role in a transitional government,” White House spokesman Josh Earnest said, adding that Assad was responsible for the deaths of tens of thousands of his own people.

Earnest said the administration’s immediate priority was removing Assad from power so he would “no longer have his hands on the weapon of war that are being used to slaughter thousands of people.”

Earlier this week, the Russian government reported that representatives of the Assad regime had agreed in principle to participate in an upcoming peace conference. But Russian Foreign Ministry spokesman Alexander Lukashevich said the regime voiced opposition to Assad’s resignation as a precondition of an eventual peace deal.