Poland will deliver four Soviet-era MiG-29 fighter jets to Ukraine “in the next few days,” President Andrzej Duda said Thursday.

Poland is the first country to formally commit to sending combat planes to Ukraine, which Kyiv says it urgently needs to repel the Russian invasion, which has become a brutal war of attrition in the eastern Donbas region.

“We will be handing over four fully operational planes,” Duda said at a joint press conference with Czech President Petr Pavel, according to French newswire AFP.

Additional planes which are “currently under maintenance” will be “handed over gradually,” Duda added, and Poland will replace the MiGs with American-made F-35s and South Korean FA-50 fighters.

After convincing its Western allies to supply Ukraine with dozens of tanks following a months-long diplomatic marathon, Kyiv has been intensively lobbying its partners in recent weeks to send modern fighter jets.

As he toured European capitals last month, Ukrainian President Volodymyr Zelenskyy made repeated pleas to the U.K. and France to provide modern jets to boost his country’s aging air force, which is mostly made up of Soviet-era planes.

Yet, Kyiv’s allies have been wary of handing over the latest generation of combat planes, such as American F-16s, out of fear it would only serve to further escalate the conflict.

So far, the U.K. has started training Ukrainian pilots as a “first step” toward sending jets, while the U.S. has welcomed two pilots on an American airbase to assess their flying skills, but will not let them operate American F-16s.

Meanwhile, countries such as France and the Netherlands have expressed openness to the idea, but steered clear of making any formal commitments.

The Polish government — one of Ukraine’s staunchest supporters since Russia launched its full-scale invasion in February 2022 — had already signaled its intention to send jets in recent days.