'Ukraine is still independent and free,' Biden said.
WARSAW, Poland -- President Joe Biden addressed the world on Tuesday from Warsaw, Poland, just days ahead of the one-year mark of Russia's brutal invasion of Ukraine.
"One year ago, the world was bracing for the fall of Kyiv," Biden said in front of the Polish Presidential Palace and a crowd of thousands. "Well, I have just come from a visit to Kyiv, and I can report that Kyiv stands strong. Kyiv stands proud. It stands tall. And most importantly, it stands free."
"When President Putin ordered his tanks to roll in Ukraine he thought we would roll over. He was wrong. The Ukrainian people are too brave. America, Europe, a coalition of nations for the Atlantic to the Pacific, we were too unified. Democracy was too strong," Biden said, blasting the Russian president by name.
"President Putin is confronted with something today that he didn't think was possible a year ago," he continued. "The democracies of the world have grown stronger, not weaker, but the autocrats of the world have grown weaker, and not stronger -- because in the moments of great upheaval and uncertainty, knowing what you stand for is most important, and knowing who stands with you makes all of the difference."
MORE: Biden makes surprise Ukraine visit, signaling strong US support in fight against Russia
National security adviser Jake Sullivan said earlier there would be no new proposals to come out of his remarks, but that the president will "appeal to the basic principles as being the way in which things should proceed from here."
"His remarks will speak specifically to the conflict in Ukraine, but they will also speak to the larger contest between those aggressors who are trying to destroy fundamental principles and those democracies who are pulling together to try to uphold them," Sullivan said in an earlier call with reporters. "You will hear in this speech vintage Joe Biden. The president has believed passionately in the themes he will discuss tonight for decades."
Biden's speech comes hours after Russian President Vladimir Putin addressed Russia's parliament, announcing the country would stop participating in the New START nuclear arms treaty with the U.S., the last remaining major arms control agreement between the two countries.
Putin said that Russia is not withdrawing from the treaty for now, but is suspending it, saying the war in Ukraine means it is not possible to allow American inspectors to visit Russian nuclear sites as agreed under the treaty.
Secretary of State Antony Blinken, reacting to the announcement in Greece, told reporters the decision was "really unfortunate and very irresponsible, but we'll be watching closely."
Sullivan stressed earlier that Biden's remarks should not be viewed as a response to Putin. He said that the date and time were selected because of the one-year anniversary of the war, adding the Biden even moved up his normal State of the Union timeframe as the trip was planned.
"We did not set the speech up as some kind of head to head, this is not a rhetorical contest with anyone else," he said. "This is an affirmative statement of values, a vision for what the world we're both trying to build and defend should look like."
In Warsaw, Biden met earlier with Polish President Andrzej Duda on Tuesday to discuss cooperation between Washington and Warsaw to aid Kyiv, particularly over Poland's role as a key staging ground for military and financial aid flowing to Ukraine. Duda publicly thanked Biden for visiting Ukraine.
Biden made a surprise visit to Kyiv on Monday, marking the first time an American president entered a warzone with no active U.S. military presence, where he saw first-hand some of the devastation caused by Russia's invasion of Ukraine.
There, Biden told Ukraine's President Volodymyr Zelenskyy that the U.S. would support Ukraine for "as long as it takes."
Biden first landed in Poland late Sunday, according to reporters traveling with him, then set off for to Ukraine for his roughly five-hour visit with Zelenskyy.
"One year later, Kyiv stands and Ukraine stands. Democracy stands," Biden said alongside Ukraine's leader on Monday. "The Americans stand with you, and the world stands with you."
The one-year mark of Russia's invasion of Ukraine falls on Friday.
ABC News' Patrick Reevell, Sarah Kolinovsky, Molly Nagle, and Tal Axelrod contributed to this report.