Slovakia on Friday became the second of Ukraine’s allies to provide MIG-29 fighter jets which Kyiv believes are crucial to repel Russia’s year-long invasion. The country will provide Ukraine with 13 such machines.

Slovakia joined Poland, which announced its delivery of the planes on Thursday. Both the NATO members neighbor Ukraine.

Bratislava’s fleet of 11 MiG-29 planes was retired last summer and most of them are not in operational condition. Slovakia will send those that are operational and the rest will go for spare parts.

The country will also supply part of its KUB air defense system, Prime Minister Eduard Heger said.

NATO allies in the former communist east such as Poland and Slovakia have been particularly vocal supporters of Kyiv. On Thursday, Poland announced it would send Ukraine four MiG-29 fighter jets in the coming days, making it the first of Kyiv’s allies to provide such aircraft.

Western countries that have provided Ukraine with arms have so far declined to send fighter jets.