The drills involve the test firing of medium-range surface-to-air missiles, the news agency said.
"Everything goes according to the plan. There is no response from the Russian Federation. Ukrainian military are ready for any developments," Ukrinform cited military spokesman Volodymyr Kryzhanivsky as saying on Ukrainian TV.
Kryzhanivsky reportedly said the drills in southern Ukraine did not pose any threat to Crimea and that Ukraine was acting in accordance with international law.
Russian Transport Minister Maksim Sokolov said Russia would evaluate its response to the drills, Russia's state-run Tass news agency reported.
The transport ministry, Rosaviatsiya, said last week that the planned missile launches were in violation of international agreements and warned they could pose a threat to flights in civil airspace above Crimea, Russia's state-run Sputnik News reported.
Poroshenko: 'No one will stop us'
Ukrainian President Petro Poroshenko said more missiles would be launched Friday, Tass reported.
"Our task is to build the air defense of Kiev and the whole of Ukraine. And no one will stop us," he is quoted as saying.
Russia annexed Crimea, a territory in the former Soviet republic of Ukraine, in March 2014 following tensions with its neighbor.
World leaders managed to install a shaky peace deal in 2015. But violence continues in the conflict zone in eastern Ukraine, and 2016 has seen an increase in casualties.
According to the United Nations, the conflict has claimed almost 10,000 lives and left hundreds of thousands displaced.
NATO Secretary General Jens Stoltenberg said in October that NATO's support for Ukraine was "unwavering" and that it did not and would not recognize Russia's "illegal annexation" of Crimea.