US President Joe Biden has announced new sanctions against Russia aimed at forcing Russian President Vladimir Putin to pay "an even steeper price" for the war in Ukraine and the death of Kremlin critic Alexei Navalny.

In a statement just ahead of the second anniversary of Russia's full-scale invasion of Ukraine, Biden also paid tribute to the Ukrainian people and appealed to US lawmakers to release funds for Kyiv.

The sanctions target 500 entities involved in the invasion and occupation of Ukraine, as well as those connected to the imprisonment of Navalny, who died last week.

"They will ensure Putin pays an even steeper price for his aggression abroad and repression at home," Biden said in a statement.

Biden said Russian President Vladimir Putin had made an error and that the war had backfired on him in several ways."

"Two years later, we see even more vividly what we’ve known since day one: Putin miscalculated badly," said Biden.

"The brave people of Ukraine fight on, unbowed in their determination to defend their freedom and future. NATO is stronger, larger, and more united than ever. And the unprecedented 50-nation global coalition in support of Ukraine, led by the United States, remains committed to providing critical assistance to Ukraine and holding Russia accountable for its aggression."

However, the US president said there was an increasing danger that the fight with Russia would be jeopardized by a lack of support in terms of weapons and ammunition provided to Ukraine. Last week, the industrial hub of Avdiivka fell to Moscow after months of bloody battles, with Kyiv's forces badly weakened by a lack of firepower.

"Two years into this war, the people of Ukraine continue to fight with tremendous courage. But they are running out of ammunition. Ukraine needs more supplies from the United States to hold the line against Russia’s relentless attacks, which are enabled by arms and ammunition from Iran and North Korea. That’s why the House of Representatives must pass the bipartisan national security supplemental bill, before it's too late."