MiG-29 fighters have arrived in Ukraine from Slovakia, according to the country's Ministry of Defense.
The Slovak government decided to donate 13 combat aircraft to the Armed Forces of Ukraine to counter the Russian invasion.
Minister of Defense of the Slovak Republic, Jaroslav Nagy, said: "This transfer was carried out by land with the maximum possible safety in mind, once again a huge thank you to all the forces involved, because in such cases it is a really important and complex logistical operation."
The first four fighters were handed over to Ukraine in March, taking off under the control of Ukrainian pilots, and Ukraine has now received the remaining nine MiG-29s.
The MiG-29 aircraft is a single-seat, twin-engine air-to-air fighter, and is a fourth-generation jet.
It was created in 1985 and was entered into service with the Soviet Union.
The MiG-29 was designed specifically to be able to compete with the American F-16 and F-15 fighters.
The Slovak government stated that the MiG-29 aircraft were donated to support the Ukrainian Armed Forces in their fight against the invading Russian army.
Jaro Nad, the Minister of Defence of the Slovak Republic, tweeted: "Proud to be on the right side, doing the right thing to help protect lives. We stand with Ukraine."