The U.S. is expected to announce Friday that it will provide about $6 billion in long-term military aid to Ukraine, U.S. officials said, adding that it will include much sought after munitions for Patriot air defense systems.

The officials said the aid package will be funded through the Ukraine Security Assistance Initiative, which pays for longer-term contracts with the defense industry and means that it could take many months or years for the weapons to arrive. The officials spoke on condition of anonymity to discuss details not yet made public.

The new funding — the largest tranche of USAI aid sent to date - will include a wide array of munitions for air defense, such as the National Advanced Surface to Air Missile System (NASAM) and the High Mobility Artillery Rocket System (HIMARS), as well as the Patriot munitions, Switchblade and Puma drones, counter drone systems and artillery.

The announcement is expected to come as Defense Secretary Lloyd Austin convenes a virtual meeting on Friday of defense officials from Europe and around the world to discuss international aid for Ukraine. The gathering — created by Austin and known as the Ukraine Defense Contact Group — has been meeting about monthly for the past two years, and is the primary forum for weapons contributions to Kyiv for the war.