WASHINGTON — On his first trip to Russia as secretary of state, Rex Tillerson came out of two hours of meetings with Russian President Vladimir Putin on April 12 saying the United States and Russia needed to take steps to halt the sharp degradation of relations between the world’s foremost nuclear powers.

But while Tillerson said he and his Russian interlocutors were looking to build on areas of common ground, their sharp differences, including over the role of President Bashar al-Assad in Syria and his culpability in the April 4 chemical weapons attack in Idlib province, seemed to overwhelm any agreement on a process for advancing a political solution to end the Syrian civil war.

“Clearly, our view is that the reign of the Assad family is coming to an end,” Tillerson said at a news conference with Russian Foreign Minister Sergey Lavrov after several hours of meetings April 12. “They have again brought this on themselves with their conduct of the war of these past few years. “

“We discussed our view that Russia, as their closest ally in the conflict, perhaps has the best means of helping Assad recognize this reality,” Tillerson said.