WASHINGTON, Oct 3 (Reuters) - The Biden administration's next security assistance package for Ukraine is expected to include four High Mobility Artillery Rocket System (HIMARS) launchers, munitions, mines and mine-resistant vehicles, two sources briefed on the $625 million package told Reuters on Monday.Register now for FREE unlimited access to Reuters.comBy using drawdown authority, the four HIMARS launchers and associated rockets, some 200 Mine-Resistant Ambush Protected (MRAP) vehicles, ammunition for Howitzers and mines, can be sent to Ukraine in the coming days.This is the first package of the U.S. government's 2023 fiscal year which is currently functioning under a stop gap-funding measure and allows President Joe Biden to drawdown up to $3.7 billion in surplus weapons for transfer to Ukraine through mid-December.Last week, the United States unveiled a $1.1 billion arms package for Ukraine which included 18 High Mobility Artillery Rocket System (HIMARS) launcher systems, accompanying munitions, various types of counter drone systems and radar systems.But last week's aid package was funded by the Ukraine Security Assistance Initiative (USAI) meaning the government has to procure the weapons from industry, rather than pulling them from existing U.S. weapons stocks."