By Patricia Zengerle WASHINGTON (Reuters) -U.S. congressional Democrats agreed to rush $39.8 billion in additional aid for Ukraine, two sources familiar with the proposal said on Monday, easing fears a delayed vote could interrupt the flow of U.S. weapons to the Kyiv government. The House of Representatives could pass the plan, which exceeds President Joe Biden’s request last month for $33 billion, as soon as Tuesday, and Senate leaders said they were also prepared to move quickly. A proposal for additional COVID-19-related funding, which some Democrats had wanted to combine with the emergency…