The Biden administration is expected to announce another substantial security assistance package for Ukraine this week, five U.S officials familiar with the matter tell NBC News.

The package is set to be about the same size as the USD 800 million military aid package Biden announced last week, three of those officials said.

Earlier in the day, Biden himself confirmed that the U.S. will send more artillery to Ukraine.

The United States has already provided more than 50 million rounds of ammunition to Ukrainian forces. But as troops go through tens of thousands of rounds a day, and fiercer fighting is expected in the coming weeks, there is an urgent need for additional aid.

Pentagon spokesman John Kirby declined to detail items in the upcoming weapons package during a briefing at the Defense Department, citing security concerns.