WASHINGTON, March 8 - U.S. intelligence leaders on Tuesday floated the idea that Vladimir Putin may seek an exit from Ukraine if his war effort continues to stall, but that escalation of the conflict is likely to happen before the Russian president considers ending his attacks.

“We assess Putin feels aggrieved the West does not give him proper deference and perceives this as a war he cannot afford to lose. But what he might be willing to accept as a victory may change over time, given the significant costs he is incurring,” Avril Haines, the director of national intelligence, told members of the House Intelligence Committee.