The U.S. has transferred to Ukraine thousands of infantry weapons and more than 500,000 rounds of ammunition that were seized more than a year ago as they were being shipped by Iran to Houthi forces in Yemen, the U.S. military said on Tuesday.

The hardware sent last week is the latest military assistance that U.S. President Joe Biden's administration has provided to Kyiv for its fight to retake territory occupied by Russia.

Democrat Biden has been blocked from providing further U.S. weaponry to Kyiv by Republican House Speaker Mike Johnson's refusal to call a vote on $60 billion in new security assistance.

With Ukrainian forces running low on weapons and munitions, especially heavy artillery rounds, the United States and its allies have been searching for new ways to arm Kyiv.

The weaponry transferred by the U.S. to Kyiv on April 4 "constituted enough materiel to equip" a Ukrainian brigade, U.S. Central Command said in a statement posted on social media platform X.

An infantry brigade typically comprises 3,500 to 4,000 troops, but the exact numbers were not known.

Iran's permanent mission to the United Nations said, "We cannot comment on weapons and armaments that have never belonged to us.”

CENTCOM said the hardware included more than 5,000 AK-47 assault rifles, machine guns, sniper rifles and rocket-propelled grenades and more than 500,000 rounds of ammunition.

The munitions were taken from four "stateless" vessels intercepted by U.S. naval ships and those of partner forces — which were not identified — between May 22, 2021 and Feb. 15, 2023, CENTCOM said.

The weapons were being sent by Iran's Islamic Revolutionary Guard Corps to the Houthis, CENTCOM said.