President Joe Biden, fresh from a visit to Kyiv, will tell US allies on Tuesday that the United States is totally behind Ukraine on the anniversary of Russia's invasion and will stress American support for NATO's eastern flank. Biden arrived in Warsaw late on Monday after a surprise visit to Kyiv, where he stood together with Ukraine President Volodomyr Zelenskiy, who is seeking more weaponry as he gears up for a spring offensive against the Russians. Biden will meet Polish President Andrzej Duda to discuss collective efforts to support Ukraine and thank Poland for helping the United States and other countries facilitate deliveries of military and humanitarian assistance. In the evening, Biden will give a speech on how the United States has helped rally the world to support Ukraine as the war enters its second year with no end in sight. "President Biden will make it clear that the United States will continue to stand with Ukraine, as you've heard him say many times, for as long as it takes," said John Kirby, the White House national security spokesperson. Before leaving Warsaw for Washington on Wednesday, Biden will meet leaders of the Bucharest Nine, the eastern flank NATO allies, to reaffirm unwavering support for their security. While Biden was in Kyiv on Monday, the State Department announced a further $460 million in US aid to Ukraine, including $450 million worth of artillery ammunition, anti-armor systems and air defense radars, and $10 million for energy infrastructure. Biden has yet to give the okay for sending fighter jets to Ukraine, as requested by Zelenskiy. Later this week, the United States will announce additional sanctions against individuals and companies that are "trying to evade sanctions and backfill Russia's war machine," a White House spokesperson said. Russia was notified before Biden's departure, officials in Washington and Moscow said, apparently to avoid the risk of an attack on Kyiv while he was there. The trip took place a day before Putin was due to make a major address on Tuesday, setting out aims for the second year of what he now calls a proxy war against the armed might of Washington and the trans-Atlantic military alliance NATO. A year ago, Biden warned skeptical allies that a massive buildup of Russian troops along Ukraine's borders was the precursor to war. At the time, even some inside his own government questioned the ability of the Ukrainians to withstand an invasion, predicting the imminent fall of the capital, Kyiv. Instead, Ukrainian fighters have held the capital and have resisted Russian attempts to control territory, helped by a massive influx of Western weapons, ammunition and equipment. The war has become a grinding conflict that US officials say could last for months or even years. Since the beginning of the war, the United States has sent more than $24 billion in security assistance to help Ukraine.