Ukrainian President Volodymyr Zelenskyy says his country will do everything it can to liberate parts of eastern Ukraine that are occupied by Russia.

Ukrainian officials said Russian missiles hit apartment buildings in the southern city of Zaporizhzhia on Wednesday. They said at least one person was killed and more than 30 wounded.

Zelenskyy strongly condemned the missile strikes, saying, "We will certainly respond to the occupier for every attack on our cities."

He also referred to the intense fighting in Bakhmut and other areas of eastern Ukraine, saying that "where there is a Ukrainian flag, there is also hope."

He added, "We will do everything so that the blue and yellow colors continue their liberation movement -- returning normal life to our entire land, from Donetsk to the border."

Russian Defence Minister Sergei Shoigu said on Wednesday that the modernization of Moscow's air defense system would be completed this year. The ministry has blamed Ukrainian forces for drone strikes on air bases in Russia.