"I announced today another $100 million drawdown using presidential drawdown authority to provide additional artillery munitions, additional interceptors for air defense and a number of anti-tank weapons as well," Austin told reporters in Kyiv.

"So you know, our support continues," said Austin, who promised Ukrainian President Volodymyr Zelensky of US support for the "long haul."

In Washington, the State Department said the assistance includes three million rounds of small-arms ammunition and equipment for HIMARS precision rocket launchers.

Secretary of State Antony Blinken said that the military support "will help meet Ukraine's immediate battlefield needs as it fights to retake its sovereign territory."

"But it is critical for Congress to take action to support Ukraine by passing the president's supplemental funding request," Blinken said in a statement.

"Helping Ukraine defend itself and secure its future as a sovereign, democratic, independent and prosperous nation advances our national security interests," he said.

With the rival Republican Party divided over Ukraine aid, President Joe Biden has sought to tie a $61 billion package for the country with $14 billion for Israel as it retaliates for a Hamas attack.

Republicans so far have only advanced the Israel portion.

The United States has provided $40 billion in security aid to Ukraine since Russia invaded in February 2022.

The funding announced Monday, as well as a series of other recent smaller packages, comes from money that was discovered after a Pentagon accounting error.