Twelve US lawmakers sent a letter to the president joe biden, urging him to send F-16 fighter jets to Ukraine on the one-year anniversary of the war in Ukraine.

The cross-party letter urges the Biden administration to provide Ukraine with “increased air superiority capability” including Kiev-requested F-16 Falcons or similar fourth-generation aircraft, “as soon as possible.”

“Given the significant time required to train even experienced pilots to operate fourth-generation fighter aircraft, we believe that a decision should be made quickly to provide Ukraine with such ‘platforms,'” the letter said.

“We note, however, that Ukrainian pilots have previously trained with the US military in 2011 and after Russia’s invasion of Crimea in 2018, and that Ukraine has reported that it has identified a list of up to 50 pilots who are now ready to begin the training in the F-16,” the letter adds.

Noting that providing such systems to Ukraine is a “strategic investment in strengthening Kiev’s military capability,” the members of Congress said “American leadership on this issue is vital.”

In a surprise visit to Kiev on Monday, Biden promised Ukraine further military aid of 500 million dollars. He said additional sanctions would be announced this week against Russian oligarchs and companies.