Minsk earlier said only 7,000 troops were participating in the Belarusian stage of the drills, which was observed by US army representatives.

"Today we are conducting the final part of the Zapad 2025 strategic exercise," said Putin, wearing a military uniform, adding: "100,000 servicemen are taking part."

Russian news agencies reported, citing the Kremlin, that soldiers from India, Iran, Bangladesh, as well as Burkina Faso, Congo and Mali were participating in the exercise, which had up to now been advertised as a joint Russian-Belarusian drill.

The Zapad manoeuvres have put NATO's eastern members on high alert following the downing of Russian drones in Poland last week, which has prompted Warsaw to shut the border with Belarus.

Putin added that the drills were aimed at exercising "repelling potential aggression against the Union State," referring to the allied entity of Russia and Belarus.

According to Polish Prime Minister Donald Tusk, the drills are designed to simulate occupation of the Suwalki corridor, a strategically important area in Poland. Warsaw said it would station around 40,000 troops near the Belarus border for the duration of the drills.

Russia said it had exercised a launch of its latest Zirkon supersonic navy missile from a frigate in the Barents Sea on Sunday. Nuclear weapons deployment planning was also drilled during the Zapad exercise, according to the Belarusian army.

Around 200,000 troops participated in the 2021 edition of Zapad, staged just months before Moscow sent forces into Ukraine.