Shipments of American weapons could begin flowing to Ukraine again soon after a long-stalled aid package becomes law, U.S. officials say, with goods from the Pentagon’s stockpiles in Germany to be shipped quickly by rail to the Ukrainian border.

The measure would provide the Ukraine war effort with about $60 billion. A sizable amount is set aside to replenish U.S. defense stockpiles, and billions more would be used to purchase U.S. defense systems, which Ukrainian officials say are badly needed.

In a statement on Saturday after the House approved the aid package, President Biden urged the Senate to swiftly take up the measure to help meet Ukrainian forces’ “urgent battlefield needs.” It was expected to do so as early as Tuesday.

For months, Ukrainian military officials have complained that political paralysis in the U.S. Congress had created critical munitions shortages in the war against Russia. Ukrainian troops on the front lines have had to ration shells, and morale has suffered.