The Defense Department said the latest shipments will bring the total value of US security assistance to Ukraine since Russia's February 2022 invasion to $37.6 billion.

"The United States will continue to work with its allies and partners to provide Ukraine with capabilities to meet its immediate battlefield needs and longer-term security assistance requirements," the Pentagon said in a statement.

The United States has been leading an unprecedented effort by NATO and other allied countries to supply Ukraine with weaponry and other aid.

The latest arms shipments come as Ukraine prepares a counter-offensive aimed at driving Russian forces back from swaths of occupied territory in the east and south of the country.

The Pentagon said the $300 million package includes munitions for Patriot air defense systems, AIM-7 air defense missiles, Avenger air defense systems and Stinger anti-aircraft missiles.

Also part of the package is ammunition for High Mobility Artillery Rocket Systems (HIMARS), 155mm and 105mm artillery rounds, 105mm tank ammunition and Zuni aircraft rockets.

The United States is sending more than 30 million rounds of small arms ammunition to Ukraine, the Pentagon said.