Ukrainian officials have urged US Congress members to press President Joe Biden's administration to send F-16 jetfighters to Kyiv, saying the aircraft would boost Ukraine's ability to hit Russian missile units with US-made rockets, lawmakers said. The lobbying came over the weekend on the sidelines of the Munich Security Conference in talks between Ukrainian officials, including Foreign Minister Dmytro Kuleba, and Democrats and Republicans from the Senate and House of Representatives. "They told us that they want (F-16s) to suppress enemy air defenses so they could get their drones" beyond Russian front lines, Senator Mark Kelly, a former astronaut who flew US Navy fighters in combat, told Reuters on Saturday evening. Biden last month said "no" when asked if he would approve Ukraine's request for Lockheed-Martin-made F-16s. Four delegations from the Senate and House combined in what members called the largest number of US lawmakers to attend Europe's premier security gathering since it started in 1963, demonstrating clear bipartisan support for Ukraine. The conference - primarily focused on Ukraine - came days before the Feb. 24 anniversary of Russia's invasion. The sides have been locked in grinding battles, mostly in the eastern Donbas region, following a string of Russian defeats. Kelly and three other lawmakers who spoke to Reuters about their talks with Ukrainian officials said they believed that support was building in Congress to provide Ukraine with F-16s, one of the world's most versatile multi-role jetfighters. Ukraine's air force has adapted US-made AGM-88 HARM air-to-surface rockets to fire from their Soviet-designed MiG-29 jetfighters. The rockets hone in on the electronic transmissions from radars of surface-to-air missile units. The Ukrainians said their pilots could more effectively target Russian S-300 and S-400 air defense missile units with the AGM-88 if the rockets were fired using the F-16s' more advanced avionics, lawmakers said. "They contended that they need that airplane for the SEAD (suppression of enemy air defenses) mission," said Kelly. "They probably think they can do a better job at taking out the S-400s." He said that while it requires at least year of training to master all of the F-16's capabilities, Ukrainian pilots could be taught to do "a limited number of things...in a few months." Support is building on both sides of the Atlantic for providing Ukraine with advanced NATO-standard jetfighters. Britain says it would provide training. Both sides, however, have been reluctant to use their airpower in a significant way since the war began. Calls to supply Ukraine with advanced jetfighters follow agreements last month by France, Britain, the United States and Germany to supply Kyiv with modern battle tanks. Washington has provided some $30 billion in military aid to Ukraine since the beginning of what Moscow calls its "special military operation."