Russia's special military operation in Ukraine is proceeding in strict accordance with the schedule and plan, President Vladimir Putin said Thursday.

"All the assigned tasks are being successfully fulfilled," Putin said at a meeting with the permanent members of Russia's Security Council.

Russian soldiers and officers "act courageously" and "fight steadfastly, with a full understanding of the rightness of their cause," he told the country's top officials.

The operation is aimed at clearing the threats caused by the West over past years right at Russian borders, including threats from nuclear weapons, said Putin.

The Russian Defense Ministry announced Wednesday that 498 Russian servicemen had been killed during the special military operation in Ukraine that started on Feb. 24.