The United States is sending a new batch of military assistance to Ukraine, the White House said Thursday, with the $450 million shipment including more rocket systems to use against Russian forces, AFP reported.

"This package contains weapons and equipment, including new High Mobility Artillery Rocket systems," White House spokesman John Kirby said.

Also included are tens of thousands of rounds of artillery ammunition and patrol boats.

The rocket systems known as HIMARS are at the top of Ukraine's wish list as the pro-Western country battles Russian forces advancing through the east of the country with the help of a significant advantage in heavy artillery.

An initial four units of the rocket system have already been delivered, kicking off the training program required for Ukrainian soldiers to operate the sophisticated and highly accurate weaponry.

With the latest shipments, the US contribution to Ukraine's military will amount so far to $6.1 billion, Kirby said.