The U.S. has approved the transfer of F-16s to Ukraine from the Netherlands and Denmark, according to officials from both countries, finally agreeing to send a long-asked-for advanced warplane to Ukrainian troops.

Secretary of State Antony Blinken earlier this week signaled his approval for the transfer in a letter to Dutch and Danish leaders. Although Denmark and Netherlands own the aircraft, the planes are made in the U.S., and deliveries must be approved by Washington.

It is a major step forward for Ukraine, which has asked for the jets since the beginning of the war more than a year ago.

Dutch Foreign Affairs Minister Wopke Hoekstra on Friday thanked Blinken “for the good and swift cooperation” on the approval of the jets.

“This marks a major milestone for Ukraine to defend its people and its country,” Hoekstra wrote on X, the platform formerly known as Twitter.

For now, the decision has opened the door to allowing the two European countries to send the prized fighter jets to Ukraine, with more exact details expected to come later.

Delivery of the aircraft and arrival on the battlefield could take months. Ukrainian pilots still need to train on the F-16s. But now, Kyiv could deploy the aircraft sooner than next spring or summer, as had been feared.

Danish officials will turn over the F-16s after getting more advanced F-35 aircraft this fall. The first four F-35s are expected to be delivered Oct. 1.

U.S. officials long argued the F-16s were not needed in the current phase of the war against Russia, rebuffing numerous requests from Kyiv since early 2022.

Ukraine operates aging, Soviet-era aircraft, and it is outgunned by Russia in the skies. Ukrainian officials have said advanced aircraft could help turn the tide of a slow-going counteroffensive in the southeast.

In May, President Biden said European allies would train Ukrainian pilots on the fighter jets, marking a reversal in the stance. A coalition of 11 allies agreed at a major NATO summit in July to begin training Ukrainian pilots in August, which is expected to begin soon.

Danish Defense Minister Kasja Ollongren said Friday the U.S. approval now “allows us to follow through on the training of Ukrainian pilots.”

“We remain in close contact with European partners to decide on the next steps,” Ollongren wrote on X.

The Associated Press contributed.