US President Joe Biden has promised Americans will protect "every inch" of NATO territory. He visited the newest member of the alliance, Finland, on Thursday. He told his hosts that the US is committed to them and to other allies.

Biden stopped in the capital, Helsinki, on his way home from the NATO summit in Vilnius, Lithuania. He met with Nordic leaders who joined him in celebrating Finland's membership. Finns have broken with decades of neutrality. Biden expect Swedes will soon follow them into the bloc.

"Both Finland and Sweden are going to add significantly to the strength, security and unanimity of NATO," Biden said. "And a stronger NATO makes the entire world stronger."

NATO leaders did not offer Ukraine an invitation during the summit. But they promised it would join eventually.

Russian President Vladimir Putin said that threat is part of why he launched what he calls the "special military operation" in Ukraine. "It will make the world a lot more vulnerable and will lead to additional tension on the international stage," he said.

NATO leaders have promised to send more weapons to Ukraine. Putin said that will "change nothing" on the battlefield. Biden said in Helsinki that Putin had "already lost" the war.