WASHINGTON (AP) — A record more than 20 NATO member nations are hitting the Western military alliance's defense spending target this year, NATO Secretary-General Jens Stoltenberg said Monday, as Russia's war in Ukraine has raised the threat of expanding conflict in Europe.

The estimated figure is a nearly fourfold increase from 2021 in the ranks of the 32 NATO members meeting the alliance's defense spending guideline. Only six nations were meeting the goal that year, before Russian President Vladimir Putin's full-scale invasion of Ukraine.

"Europeans are doing more for their collective security than just a few years ago," Stoltenberg said in a speech at the Wilson Center research group before meeting with President Joe Biden later Monday at the White House.

NATO members agreed last year to spend at least 2% of their gross domestic product on defense. The surge in spending reflects the worries about the war in Ukraine.

Some countries also are concerned about the possible reelection of former President Donald Trump, who has characterized many NATO allies as freeloading on U.S. military spending and said on the campaign trail that he would not defend NATO members that don't meet defense spending targets.

Stoltenberg's visit is laying the groundwork for what's expected to be a pivotal summit of NATO leaders in Washington next month. The mutual-defense alliance has grown in strength and size since Russia's invasion of Ukraine two years ago, with both Sweden and Finland joining.

Defense spending by many European countries fell after the 1991 collapse of the Soviet Union seemed to neutralize what was then the prime security threat to the West.

But after Russia seized Ukraine's Crimean Peninsula in 2014, NATO members unanimously agreed to spend at least 2% of their GDP on defense within a decade. The full-scale invasion that Putin launched in 2022 spurred European countries newly on the front line of a war in the heart of Europe to pour more resources into meeting that target.