WARSAW, Poland, and WASHINGTON — Slovak Prime Minister Eduard Heger has announced his country will deliver 13 out-of-commission Mikoyan MiG-29 fighter jets to Ukraine as part of Bratislava’s support to the nation’s struggle against the Russian invasion.

“Promises must be kept,” Heger said in a tweet on Friday, adding that Slovakia’s military aid was designed to help Ukraine defend itself and “entire Europe against Russia.”

The latest move comes one day after Polish President Andrzej Duda declared his country will supply the first four MiG-29 jets to Ukraine in the coming days, with more aircraft to be delivered in the future.

Slovakia secured 24 single-seater and twin-seater Soviet-made fighters following Czechoslovakia’s dissolution, according to data from the Slovak Ministry of Defence. Of these, the 11 remaining operational aircraft were withdrawn from service last August.

Commenting on the Slovak prime minister’s announcement, the country’s Defence Minister Jaroslav Naď said in a Facebook post on Friday: “Slovakia is donating retired, unused and unusable MiG-29s.” He added that “Ukraine has a plant where they can service them, it has trained pilots” who know how to fly such jets.

In addition to the fighters, Slovakia will also supply elements of its Soviet-built 2K12 KUB air defense systems to Ukraine, local news agency TASR reported. In return for the donated gear, Naď said earlier this week the country hopes to receive about €200 million ($213 million) from the European Union’s European Peace Facility, and some $700 million worth of weapons and military equipment from the United States.

The Polish president said his country’s air force will replace the donated Soviet-made fighters with some of the 48 FA-50 light attack aircraft Poland’s Ministry of National Defence ordered from South Korea in September 2022. The first 12 FA-50s are to be supplied this year, and the remaining 36 jets in the years 2025 to 2028.

In the meantime, Slovakia is awaiting the procurement of 14 F-16 Block 70/72 fighters bought from the U.S. to protect the country’s skies. Deliveries are expected to begin in 2024.

The two eastern European countries’ warplane pledges have not swayed Washington to follow suit by donating F-16s, White House national security spokesman John Kirby told reporters on Friday.

“We knew that this was something that the Slovakian government was considering doing so it’s not a surprise that they moved in this direction,” Kirby said. “No, it doesn’t have any impact or effect on our own sovereign decision making when it comes to the F-16.”

The U.S. argument is that Ukraine’s military uses Russian-made MiGs and can absorb them quickly but not the Lockheed Martin-made F-16′s.

“They’re comfortable with those fighter aircraft. They know how to fly them and they know how to maintain them; they know how to operate them and use them in a battlefield situation,” Kirby said, calling the MiGs “additive to the fighter aircraft capabilities that the Ukrainian Air Force has at their disposal.”

Kirby called Slovakia “a terrific supporter” of efforts to aid Ukraine, to which the U.S. has pledged more than $30 billion in military aid since the invasion.

Jaroslaw Adamowski is the Poland correspondent for Defense News.

Joe Gould was the senior Pentagon reporter for Defense News, covering the intersection of national security policy, politics and the defense industry. He had previously served as Congress reporter.

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