WATCH: Putin prepared for ‘prolonged conflict’ in Ukraine, says U.S. intelligence chief

The U. S. intelligence director believes that Russian President Vladimir Putin is preparing for a “prolonged conflict” in Ukraine and considers a Russian victory in the Donbas to be key in winning the war.

Watch the hearing in the player above.

U.S. Director of National Intelligence Avril Haines testifying before the Senate Armed Services committee on Tuesday said: “We assess President Putin is preparing for a prolonged conflict in Ukraine, during which he still intends to achieve goals beyond the Donbas.”

WATCH: No sign Russia ‘eager to engage’ in peace talks to end Ukraine war, says White House

Haines added that the war is becoming one of attrition and the outcome in Ukraine is uncertain, moving toward a “unpredictable and potentially escalatory trajectory.”

Lt. Gen. Scott Berrier, who leads the Defense Intelligence Agency, says eight to 10 Russian generals have been killed during the war in Ukraine.

Berrier disclosed the estimate while testifying before the Senate committee.

Berrier told senators that because Russia lacks a non-commissioned officer corps, its generals have to go forward into combat zones and end up in dangerous positions.

Russia pummeled the vital port of Odesa, Ukrainian officials said Tuesday, an apparent effort to disrupt supply lines and Western weapons shipments critical to Kyiv’s defense.

Ukraine’s ability to stymie a larger, better-armed Russian military has surprised many who had anticipated a much quicker end to the conflict.

With the war now in its 11th week and Kyiv bogging down Russian forces and even staging a counteroffensive, Ukraine’s foreign minister appeared to suggest the country could expand its aims beyond merely pushing Russia back to areas it or its allies held on the day of the Feb. 24 invasion.