The US Defense Department told lawmakers Tuesday it estimates between 2,000 and 4,000 Russian soldiers have been killed in Moscow's nearly two-week-old invasion of Ukraine.

The assessment came as US defense and intelligence leaders painted a stark picture of an aggressive and aggrieved Russian President Vladimir Putin and a likelihood that he will continue to propagate a full-scale invasion of neighboring Ukraine in the face of massive global opposition.

Asked at a House Intelligence Committee hearing how many Russian troops have died to date in the military operation, Lieutenant General Scott Berrier, director of the Pentagon's Defense Intelligence Agency, said "somewhere between two (thousand) and 4,000."

Berrier did add however that the estimate is considered "low confidence" because it was put together using a combination of intelligence sources and open source data.

Russia, in a rare release of military death figures, said on March 2 that 498 of its soldiers have died. Ukraine at the time said it believed the figure was higher.

US defense and intelligence leaders, including CIA Director William Burns (C) told US lawmakers Russian President Vladimir Putin was likely to keep the Ukraine war going despite an estimated 2,000 to 4,000 Russian troop deaths so far
US defense and intelligence leaders, including CIA Director William Burns (C) told US lawmakers Russian President Vladimir Putin was likely to keep the Ukraine war going despite an estimated 2,000 to 4,000 Russian troop deaths so far AFP / Stefani Reynolds

Central Intelligence Director William Burns told the House panel that he believes Ukraine and the Moscow-driven war is a matter of "deep personal conviction" for Putin.

"He's been stewing in a combustible combination of grievance and ambition," Burns said, adding he expects "an ugly next few weeks in which (Putin) doubles down" in Ukraine "with scant regard for civilian casualties."

But he also expressed confidence that the Ukrainians will continue "to resist fiercely and effectively."

The Director of National Intelligence, Avril Haines, told the lawmakers that Putin did not anticipate the full scope of the global economic, trade and diplomatic pushback against Russia.

But she also said it was DNI's assessment that Putin is "unlikely to be deterred from such setbacks," and sees the conflict as "a war he cannot afford to lose."