President Volodymyr Zelensky on Tuesday asked parliament to appoint a former Ukrainian envoy to NATO, Vadym Prystaiko, as new foreign minister and to sack General Prosecutor Yury Lutsenko.
Zelensky also dismissed 15 heads of the regional state administrations and appointed acting heads in 12 regions.
At a meeting of the Constitutional Court, the president said that his decision to dissolve the parliament, Verkhovna Rada, and call snap elections, was legal.
Two MPs earlier submitted a motion to the court, arguing that the move contradicts the constitution.