U.S. President Joe Biden said Tuesday that democracies around the world have become "stronger" after Russia launched its invasion of Ukraine nearly a year ago, while reaffirming Washington's continued support for Kyiv with its allies.

A day after making a surprise visit to Kyiv, Biden repeatedly stressed the importance of democracy and freedom in remarks delivered from the gardens of the Royal Castle in Warsaw, declaring that "Ukraine will never be a victory for Russia. Never."

U.S. President Joe Biden delivers a speech at the Royal Castle Arcades during his visit in Warsaw, Poland, on Feb. 21, 2023. (Anadolu Agency/Getty/Kyodo)

Biden's speech came hours after Russian President Vladimir Putin's long-delayed state-of-the-nation address, in which he showed no signs of ending the war and said Moscow will suspend its participation in the New START treaty.

The treaty is the only remaining nuclear arms control pact with the United States, with Putin's latest message to Washington heightening tensions between the two nations over the conflict in Ukraine.

Biden, speaking three days before the anniversary of Russia's invasion, singled out Putin by name a number of times and said, "The democracies of the world have grown stronger, not weaker. But the autocrats of the world have grown weaker, not stronger."

He pledged U.S. support for Ukraine will "not waver," adding, "NATO will not be divided. And we will not tire."

"President Putin's craven lust for land and power will fail, and the Ukrainian people's love for their country will prevail," he told an audience of thousands. "Democracies of the world will stand guard over freedom today, tomorrow, and forever."

While Putin claimed that sanctions from the West had no effect on the Russian economy, the U.S. president revealed that additional punitive measures against Moscow will be announced later this week by Washington and its allies.

At the castle in the Polish capital, where Biden last spoke weeks after Russia launched the invasion, he did not, however, touch on the suspension of the arms treaty.

Instead, he sought to discredit Putin's assertion that Western nations are to blame for escalating the conflict, and emphasized the points about the war he wanted to convey to the people of Russia.

"The United States and the nations of Europe do not seek to control or destroy Russia. The West was not plotting to attack Russia, as Putin said today," he said. "This war was never a necessity. It's a tragedy. President Putin chose this war. Every day the war continues is his choice."

Biden also underscored the strength of the North Atlantic Treaty Organization, saying that the security alliance of 30 nations from North America and Europe is now more unified than ever, contrary to Putin's wishes that it would fracture.

"The United States, together with our allies and partners, are going to continue to have Ukraine's back as it defends itself," he said.

He added that the United States will next year host a NATO summit and will celebrate the 75th anniversary of the "strongest defensive alliance in the history of the world" with all its members.