The call follows the April 20 vote in the U.S. House of Representatives, when a key foreign aid package for U.S. allies was passed, providing over $60 billion in assistance for Ukraine. Zelensky thanked the U.S. president for his "unwavering support for Ukraine and true global leadership."Zelensky said that Biden assured him "that the package will be approved quickly and that it will be powerful, strengthening our air defense as well as long-range and artillery capabilities."U.S. Senator Mark Warner said on April 21 that shipments that include long-range missile systems could be ready to be delivered within days.  The U.S. could begin transferring long-range Army Tactical Missile Systems (ATACMS) to Ukraine "by the end of the week," pending White House approval, Warner said.