The U.S. estimates that between 2,000 and 4,000 Russian troops have been killed in the 12-day invasion of Ukraine, according to Defense Intelligence Agency Director Scott Berrier, who said the Russian military had a “bad plan.”

Berrier, testifying at Congress’ annual worldwide threats hearing on Tuesday, said its challenging to determine a precise figure and he has just “low confidence” in the range he provided.

But a Russian death toll in the thousands is stunning. For reference, an estimated 2,448 American service members were killed in the U.S.’s two decade military campaign in Afghanistan.

Appearing at the same Congressional hearing, Director of National Intelligence Avril Haines predicted a “persistent and significant insurgency” from the Ukrainian people.

NBC News adds:

Haines said American intelligence agencies assess that “Moscow underestimated the strength of Ukraine’s resistance and the degree of military challenge,” but that Putin may feel compelled to fight on nonetheless, as the Russian military operates “with reckless disregard” for the safety of non-combatants.

She said it was unclear if Russia will continue the “maximalist plan” to seize all of Ukraine, and that the economic crisis Russia is now experiencing because of international sanctions is “driving domestic political opposition to Putin.”

Putin did not anticipate the resistance from the West and the pullback from Russia by international business interests, she added.

A worldwide threats assessment document prepared by U.S. intelligence agencies before the invasion claims Putin does not want to engage militarily with the U.S.

CIA Director William Burns also testified at Tuesday’s hearing and noted that China’s authoritarian president, Xi Jinping, is “unsettled” by both Russia’s inability to wage a quick and successful war and the West’s unified condemnation of the conflict. Chinese leaders are also worried that the invasion will trigger a global recession at a time when they badly need economic growth.