Russian gymnast Ivan Kuliak, who sported an insignia linked to the invasion of Ukraine on a medals podium, was blasted for his "shocking behaviour" on Sunday.

Kuliak's shirt had the letter 'Z' prominently placed as he stood next to Ukraine's Kovtun Illia, the gold medallist at a Gymnastics World Cup event in Doha. The 'Z' has been seen daubed on Russian tanks and vehicles in Ukraine and has come to symbolise support for the invasion. Kuliak had won the bronze medal on Saturday.

"The International Gymnastics Federation confirms that it will ask the Gymnastics Ethics Foundation to open disciplinary proceedings against Ivan Kuliak following his shocking behaviour at the Apparatus World Cup in Doha, Qatar," a statement from the ruling body said. It had already been decided that from Monday all Russian and Belarusian gymnasts will be banned from future competitions.

Several cities and airbases in Ukraine have been bombed, shelled or hit with ballistic missiles since Russia launched its 11-day-old invasion.

Zelensky took the opportunity to renew his demand that Western powers enforce a no-fly zone over Ukraine to prevent more Russian attacks.

"We repeat every day: close the sky over Ukraine. Close for all Russian missiles, for Russian combat aircraft, for all their terrorists," he said.

"If you don't, if you don't give us at least planes so we can protect ourselves, there's only one thing to conclude; you want us to be killed very slowly."