The US Secretary of Defense has said his country wants to see Russia "weakened to a degree" so that it cannot repeat its invasion of Ukraine.
Lloyd Austin was speaking after he and Secretary of State Antony Blinken visited the Ukrainian capital Kyiv, meeting Ukraine's President Volodymyr Zelensky.
He said Russia "has already lost a lot of military capability and a lot of its troops", adding: "We want to see them not have the capability to very quickly reproduce that capability."
Mr Austin said the United States would do everything it could to help Ukraine win the war against Russia, confirming more than $300m (£234m) in foreign military financing and approving a $165m (£128m) sale of ammunition.
"We want to see Ukraine remain a sovereign country, a democratic country, able to protect its sovereign territory," Mr Austin said.
"The first step in winning is believing that you can win," he added.
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"And so they believe that we can win. We believe that we can win, they can win if they have the right equipment, the right support," he said.
Mr Austin also said the conflict in Ukraine would evolve, and as a result, the needs of Ukrainians would change.
"As those needs change, we'd like to be one step ahead," he said.
Mr Blinken said that Ukraine can win the war, adding: "Russia is failing. Ukraine is succeeding."
"Russia has sought, as its principal aim, to totally subjugate Ukraine, to take away its sovereignty, to take away its independence.
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"That has failed.
"It sought to assert the power of its military and its economy.
"We, of course, are seeing just the opposite: a military that is dramatically underperforming, an economy as a result of sanctions, as a result of a mass exodus from Russia, that is in shambles."
Mr Blinken insisted the US wants to see Russian aggression in Ukraine ended through diplomacy and dialogue, confirming US diplomats will return to Ukraine this week.
However, he also said US support will continue to strengthen Ukraine on the battlefield.
"The bottom line is this: we don't know how the rest of this war will unfold, but we do know that a sovereign, independent Ukraine will be around a lot longer than Vladimir Putin's on the scene," he said.