Russian President Vladimir Putin has appointed acting governors to five regions of the country hours after their predecessors announced they were stepping down.

The Kremlin said on May 11 that Putin met a day earlier with the officials he had chosen to appoint as acting governors of the Kirov, Ryazan, Saratov, and Tomsk regions, and the Republic of Mari El.

While Putin has often replaced officials ahead of elections with the aim of fielding stronger candidates backed by the Kremlin, the timing of the move has raised speculation that he may be frustrated at the failure of Russia's army to quickly defeat Ukraine after invading it in late February.

In the changeover, Putin named Pavel Malkov, the chairman of Russia's Statistics Agency, as the acting governor of the Ryazan region, while Roman Busargin was made the acting governor of the Saratov region; Aleksandr Sokolov the acting governor of the Kirov region; Vladimir Mazur the acting governor of the Tomsk region; and Yury Zaitsev the acting head of the Republic of Mari El.

All five are known as strong supporters of Putin.

Regional elections are scheduled across Russia for September 11.