(NewsNation) — One day after his surprise visit to Kyiv, President Joe Biden delivered remarks in Warsaw, Poland, directly addressing Russian President Vladimir Putin and reassuring the world that Ukraine stands strong.

“Kyiv stands strong. Kyiv stands proud. It stands tall, and most important of all it stands free,” Biden said during his speech.

Biden said that Putin’s war of conquest and autocracy is failing. He highlighted the commitment of Poland and other allies to Ukraine over the past year.

“Our support for Ukraine will not waver, NATO will not be divided and we will not tire,” Biden said. “Ukraine is still independent and free.”

The president commended the commitment to Ukraine from Poland, the U.S. and allied countries across the world.

“This war was never a necessity,” Biden said. “It’s a tragedy. President Putin chose this war. Every day the war continues is his choice.”

Early Tuesday morning, Biden consulted with allies from NATO’s eastern flank in Poland and met with Polish President Andrzej Duda.

“The United States needs Poland and NATO as much as Poland and NATO need the United States,” Biden told Duda.

Biden argued that NATO was stronger than it has ever been and that the U.S.-Poland alliance might be the single most consequential in history to maintain security in Europe.

Jamil Jaffer, the founder and executive director of the National Security Institute, said that Biden’s visit to Ukraine and announcement of the new military aid to Ukraine was designed to show the strength of the coalition standing behind Ukrainian President Volodymyr Zelenskyy and his nation’s forces.

Biden’s planned speech followed Putin’s annual address to the federal assembly in Moscow.

In his long-delayed state-of-the-nation address, Putin again attacked the expansion of the NATO military alliance, saying the U.S. sees the war as an “anti-Russian project,” or a proxy war, and that the aim is to seize Russian lands.

Putin cast Russia — and Ukraine — as victims of Western double-dealing and said Russia, not Ukraine, was the one fighting for its very existence.

“We aren’t fighting the Ukrainian people,” Putin said in a speech days before the war’s first anniversary on Friday. Ukraine “has become hostage of the Kyiv regime and its Western masters, which have effectively occupied the country.”

The Russian president is also, again, claiming that the invasion of Ukraine was necessary to defend Russia, saying, “They did not leave us any other option.”

Putin also declared Tuesday that Moscow was suspending its participation in the New START treaty — the last remaining nuclear arms control pact with the United States — sharply upping the ante amid tensions with Washington over the fighting in Ukraine.

U.S. State Department spokesperson Ned Price responded to Putin in an interview Tuesday morning, calling Putin’s announcement “irresponsible.” Price said the U.S. is watching “very carefully” what actual steps Russia takes next in regard to the treaty.

“We haven’t seen any reason to change our nuclear posture just yet,” Price said. “We’ve been calling on Russia for some time to meet with us so we can make these inspections to ensure Russia is in compliance with the treaty.”

White House national security adviser Jake Sullivan said that Biden’s Royal Castle speech would be “vintage Joe Biden” and that the Democratic president would lay out that the action democracies take in the coming years will have reverberations for years to come. Sullivan also said that Biden’s address would not be “some kind of head-to-head” with Putin’s.

While Biden looked to use his whirlwind trip to Europe as a moment of affirmation for Ukraine and allies, the White House has also emphasized that there is no clear endgame to the war in the near term and the situation on the ground has become increasingly complex.

Biden’s speech came at an important time as China’s top diplomat arrived in Moscow for meetings at the same time Biden arrived in Europe.

The administration on Sunday revealed it has new intelligence suggesting that China, which has remained on the sidelines of the conflict, is now considering sending Moscow lethal aid. Secretary of State Antony Blinken said it could become a “serious problem” if Beijing follows through.

Jaffer said that if the Chinese up the ante, it could force the U.S. to double down and could lead to a cycle of escalation in the region, and potentially in a larger situation.

On Wednesday, Biden will consult with Duda and other leaders of the Bucharest Nine, a group of the easternmost members of NATO military alliance.

The Associated Press contributed to this report