Foreign volunteers fighting against Russia can obtain Ukrainian citizenship if they wish. This also applies to their family members - Klymenko

This was stated by Interior Minister Ihor Klymenko in an interview with Natalia Moseychuk, Censor.NET reports.
"The Cabinet of Ministers has adopted a number of resolutions that define the procedure for obtaining citizenship in the future. Moreover, all the documents that these citizens have, including temporary residence permits in Ukraine, are all valid even if they have expired. I am confident that these citizens of other countries who participated in the armed resistance to the Russian army will all receive Ukrainian citizenship if they have such a desire," he said.
According to Klymenko, this also applies to their family members.