Crimea-based PFC Sevastopol and FC Tavriya have been cut from this season's Ukrainian Premier League following the annexation of the peninsula by Russia, the football federation said.
Four clubs from the eastern part of Ukraine, including champions Shakhtar Donetsk, must relocate temporarily until the military confrontation with pro-Russian separatists is settled.
Hundreds of people have been killed in three months of fighting in eastern Ukraine as government forces try to end the rebellion in towns and cities across the Russian-speaking region.
"We have confirmed new regulations — the number of Premier League teams is 14 (reduced from 16) and the championship starts on July 26," said federation executive Igor Gataullin on Thursday.
Shakhtar need to find a venue for their Champions League matches after European soccer's ruling body UEFA told the Ukrainian federation that it considers Kiev and Lviv as the only cities safe enough to host games in the near future.
Cities such as Donetsk, Kharkiv, Mariupol, Zaporizhya and Luhansk have been deemed off-limit.
Local media have speculated that Shakhtar might opt to play outside Ukraine, with Bucharest among the possible venues.
Shakhtar will play in the Champions League group stage next season and Metalist Kharkiv and Zorya Luhansk have secured places in the Europa League.