Ukrainian President Volodymyr Zelenskyy on Saturday dismissed several of Kyiv's senior envoys abroad including the country's outspoken ambassador to Germany, the presidential website said.
In a decree that gave no reason for the move, Zelenskyy announced the sacking of Ukraine's ambassadors to Germany, India, the Czech Republic, Norway and Hungary.
It was not immediately clear if the envoys would be assigned new positions.
Zelenskyy has urged his diplomats to drum up international support and military aid for Ukraine as it tries to fend off Russia's Feb. 24 invasion.
Kyiv's relations with Germany, which is heavily reliant on Russian energy supplies and also Europe's biggest economy, are particularly sensitive.
Andriy Melnyk, who was appointed by Zelenskyy's predecessor as ambassador to Germany in late 2014, is well-known among politicians and diplomats in Berlin.
The 46-year-old regularly engages in outspoken social media exchanges, and has branded politicians and intellectuals who oppose arming Ukraine to fight the Russian invasion as appeasers.
He once accused German Chancellor Olaf Scholz of behaving like an "offended liver sausage" when Scholz did not immediately accept an invitation by Zelenskyy to visit Kyiv.
Kyiv and Berlin are currently at odds over a German-made turbine undergoing maintenance in Canada. Germany wants Ottawa to return the turbine to Russian natural gas giant Gazprom to pump gas to Europe.
Kyiv has urged Canada to keep the turbine, saying shipping it to Russia would be a violation of sanctions imposed on Moscow.