By Mike Stone and Steve Holland

WASHINGTON (Reuters) - The United States plans to announce as soon as Tuesday a new military aid package for Ukraine worth up to $400 million, primarily comprised of artillery, air defense missiles and ground vehicles as Ukraine's counteroffensive grinds on, three U.S. officials said on Friday.

The U.S. is not including cluster munitions in this weapons assistance package, two of the officials who spoke on condition of anonymity said. The U.S. first sent dual-purpose improved conventional munitions (DPICM) - a cluster munition fired from a 155 millimeter Howitzer cannon to Ukraine earlier in July.

Included in the package are several Stryker armored personnel carriers, mine clearing equipment, munitions for National Advanced Surface-to-Air Missile Systems (NASAMS), munitions for High Mobility Artillery Rocket Systems (HIMARS), anti-tank weapons including TOW and Javelin and munitions for Patriot and Stinger anti-aircraft systems, according to the officials.

The package was still being finalized and could change.

The package would be funded using Presidential Drawdown Authority, or PDA, which authorizes the president to transfer articles and services from U.S. stocks without congressional approval during an emergency. The material will come from U.S. excess inventory.

The security assistance package would be the 43rd approved by the United States for Ukraine since the Russian invasion in February 2022, for a total of more than $41 billion.

(Reporting by Mike Stone and Steve Holland in Washington; Editing by Cynthia Osterman)