The Pentagon in June revealed that it had another $6.2 billion to disperse to Ukraine than it previously thought after a mistake in how it calculated prices for some weapons.

In the first of an expected series of packages with the restored funds, the United States will send munitions for Patriot air defense systems, 12 million rounds of small arms ammunition and grenades, and ammunition for Himars, the multiple-rocket launchers that have proven critical on the ground, according to the State Department.

"Russia started this war and could end it at any time by withdrawing its forces from Ukraine and stopping its brutal attacks," Secretary of State Antony Blinken said in a statement announcing the latest aid.

"Until it does, the United States and our allies and partners will stand united with Ukraine, for as long as it takes," he said.

President Joe Biden's administration has sent $43 billion in security assistance since Russia invaded Ukraine last year, and last week asked Congress to approve $13 billion more.

While most mainstream US lawmakers of both parties support assistance to Ukraine, recent polls have shown softening US support for military assistance.

Former president Donald Trump, the frontrunner for the Republicans' 2024 nomination, has criticized assistance to Ukraine, saying that he expects Russia to triumph and that European allies should do more.