The key to establishing peace in Ukraine will be making it impossible for Russia to never occupy Ukraine, President of the United States Joseph Biden said.

"Peace looks like making sure Russia never, never, never, never occupies Ukraine. That's what peace looks like. And it doesn't mean NATO, they are part of NATO. It means we have a relationship with them like we do with other countries, where we supply weapons so they can defend themselves in the future," he said in an interview with Time published on Tuesday.

The U.S. President recalled saying that he is not prepared to support "the NATOization of Ukraine." It was due to corruption issues which he saw when spending a month in Ukraine as a Senator and Vice President.

"And so, the point is, though, that if we ever let Ukraine go down, mark my words: you'll see Poland go, and you'll see all those nations along the actual border of Russia, from the Balkans and Belarus, all those, they're going to make their own accommodations. […] No, we're on a slippery slope for war if we don't do something about Ukraine. It's just not gonna…anyway…" he said.

Biden also stressed that the United States has been able to put 50 nations together to help in Ukraine, adding that Europe has spent more money to support Ukraine than the United States has, collectively.