HELSINKI, Finland — President Biden said Thursday that Russian President Vladimir Putin has “already lost” his war in Ukraine and that it’s only a matter of time until he accepts it as a fact.

Biden made the bold pronouncement during a visit to Finland to celebrate the longtime neutral Russian neighbor’s admission to NATO this past April following Moscow’s invasion in February 2022.

“Putin’s already lost the war,” Biden said during a joint press conference with Finnish President Sauli Niinistö.

“Putin has a real problem: How does he move from here? What does he do? And so, the idea that there’s going to be, what vehicle is used,” the president went on before reiterating that the Russian tyrant “could end the war tomorrow. He could just say, ‘I’m out.'”

“There’s no possibility of him winning the war in Ukraine,” Biden added. “He’s already lost that war.”

The American president effectively declared victory by Kyiv even as it carries out a slow-moving counteroffensive meant to take back Russian-controlled areas of southern and eastern Ukraine.

In a bid to bolster Ukrainian efforts to regain ground, Biden last week authorized the transfer of controversial cluster munitions, which are banned by more than 100 countries — including key NATO allies — because they can injure or kill civilians long after wars end.

While in Finland, Biden met with the leaders of Nordic countries Denmark, Iceland, Norway and Sweden — after meeting with a larger group of NATO leaders on Tuesday and Wednesday during the alliance’s annual summit in Lithuania.

The US president revealed during the Helsinki press conference that the American government isn’t sure of the whereabouts of Yevgeny Prigozhin, the Wagner Group mercenary leader who led a brief insurrection against Putin last month.

“I’m not even sure, we’re not even sure, where he is,” Biden said amid speculation that Prigozhin may be dead rather than living in exile in Belarus as publicly announced.

“If I were he, I’d be careful what I ate. I’d be keeping my eye on my menu,” the president added jokingly.

Biden also said that Ukraine “will join NATO” — but not until after the war with Russia ends.

“No one can join NATO while a war is going on where a NATO nation is being attacked, because that guarantees that we’re in a war — and we’re in a third world war,” Biden said.

The president added: “I think what Finland’s joining NATO does, and Sweden as well … is it just makes the world safer. It significantly increases the prospect that there’s less likely to be war.”

The NATO summit in Vilnius was marked by new pledges of support for Ukraine’s defense and tense words between Ukrainian President Volodymyr Zelensky and US and UK leaders over his demand that NATO extend an offer of membership.

Zelensky on Tuesday blasted the alliance’s “absurd” decision to stall an invitation until after the war ends, but on Wednesday conceded it was “logical” that Western leaders feared sparking a world war with Russia and said he viewed the summit as a “success” because of the “great unity from our leaders and security guarantees” for his country.