President Joe Biden welcomed NATO’s 75th anniversary Thursday, as the security alliance hosted new member Sweden for the first time at a major meeting – and as Ukraine eagerly hopes for an invitation to join at an upcoming Washington summit.

Biden, in a statement, welcomed the recent addition of new members Finland and Sweden, saying “we must choose to protect this progress and build on it.”

“This is the greatest military alliance in the history of the world,” Biden said. “But it didn’t happen by accident, nor was it inevitable. Generation after generation, the United States and our fellow Allies have chosen to come together to stand up for freedom and push back against aggression — knowing we are stronger, and the world is safer, when we do.”

Biden’s Democratic allies agreed.

FILE - NATO Secretary General Jens Stoltenberg, right, speaks with United States President Joe Biden during a meeting of the NATO-Ukraine Council during a NATO summit in Vilnius, Lithuania, July 12, 2023.

FILE – NATO Secretary General Jens Stoltenberg, right, speaks with United States President Joe Biden during a meeting of the NATO-Ukraine Council during a NATO summit in Vilnius, Lithuania, July 12, 2023.

“Despite Putin’s attempts to splinter our alliance with his war against Ukraine, the transatlantic partnership is more united than ever before, thanks to the determined leadership of Joe Biden,” said former House Speaker Nancy Pelosi. “On this monumental anniversary, we reaffirm that America’s commitment to NATO remains bipartisan and ironclad – and that we will never waver in our defense of democracy.”

NATO allies have been increasingly unnerved by the prospect of former Republican President Donald Trump returning to the White House if he defeats Biden in the November 5 U.S. presidential election.

As president, Trump frequently complained that numerous NATO countries were not meeting NATO’s recommendation that they spend 2% of their country’s economic output on defense.

In February, at a campaign rally, Trump recounted what he said was a conversation he had when he was the U.S. leader with the “president of a big country.”

“Well sir, if we don’t pay, and we’re attacked by Russia – will you protect us?” Trump quoted the unnamed leader as saying.

“I said: ‘You didn’t pay? You’re delinquent?’ He said: ‘Yes, let’s say that happened.’ No, I would not protect you. In fact, I would encourage them (Russia) to do whatever the hell they want. You got to pay,” Trump said.

Some analysts argue that the alliance remains relevant, citing Russia’s aggression in Ukraine.

“Nearly a billion people sleep more soundly at night under NATO’s protective umbrella,” Robert Benson, a senior policy analyst at the Center for American Progress, said in a message sent to VOA. “Yet a small but vocal minority views the alliance as a relic of the past, an albatross, or a distraction –– all this in a world where Russian imperial ambition has once again threatened international peace and security. The United States must continue to support Ukraine and to strengthen NATO, not out of charity or moral obligation, but because it makes us safer here at home.”

The United States will host NATO’s 75th anniversary summit in Washington in July.