The Biden administration's next security assistance package for Ukraine is expected to be $1 billion, one of the largest so far, and include munitions for long-range weapons and armoured medical transport vehicles, three sources briefed on the matter told Reuters on Friday. Last Monday, the Pentagon announced a separate security assistance package for Ukraine valued at up to $550 million, including additional ammunition for High Mobility Artillery Rocket Systems (HIMARS). The new package would be funded under the Presidential Drawdown Authority (PDA), in which the president can authorize the transfer of articles and services from U.S. stocks without congressional approval...