The U.S. Air Force on Monday prepared a shipment of ammunition, weapons, and other equipment headed to Ukraine. Washington has said it would continue to support Ukraine amid concerns in Kyiv and among its Western allies over the tens of thousands of Russian troops amassed on its border. Russia denies planning a military offensive. The United States has provided over $2.5 billion in military aid since 2014, including Javelin anti-tank missiles, coastal patrol boats, Humvees, sniper rifles, reconnaissance drones, radar systems, night vision, and radio equipment. A bipartisan group of U.S. senators last week promised further supplies that could include Stinger anti-aircraft missiles, small arms, and boats.