An estimated 2,500 troops from the Russian-led Collective Security Treaty Organization (CSTO) have opened military exercises in parts of Belarus that border NATO members Poland and Lithuania.
The Combat Brotherhood 2023 exercises, which opened on September 1 and are scheduled to last through September 6, include troops from Russia, Belarus, Kyrgyzstan, Kazakhstan, and Tajikistan. Armenia is also a member of the CSTO but did not send troops.
Kazakh Defense Minister Ruslan Zhaqsylyqov said that the Kazakh military would take part in the CSTO exercises but would not send military equipment.
The Belarusian Defense Ministry said the exercises were to prepare for joint operations, including responses to a nuclear accident, and intelligence sharing.
The exercises are being observed by representatives of China, Iran, Saudi Arabia, and Mongolia. Alyaksandr Lukashenka, the authoritarian leader of Belarus, announced on August 31 that Minsk had also invited representatives of Poland to act as observers.
Valer Ravenka, an assistant to the Belarusian defense minister, said on X, the social media platform formerly known as Twitter, that Poland "preliminarily" refused the invitation.
There has been no comment from Poland on the invitation, but Polish Foreign Minister Zbigniew Rau said the purpose of the military exercises was to destabilize the region.
Ukrainian General Serhiy Nayev said his country reinforced its border with Belarus ahead of the exercises.
"For us, any actions on the part of the enemy, including conducting exercises on their territory, is a certain aspect of increasing the danger," Nayev said.
Belarus hosts Russian forces and equipment that have been used in the war in Ukraine, but Belarusian troops have not taken part. The Russian forces in Belarus include Wagner mercenary group fighters.
Wagner relocated some of its troops to Belarus under a deal brokered by Lukashenka after the mercenary group in June launched a mutiny aimed at ousting rivals of Wagner leader Yevgeny Prigozhin from the Russian Defense Ministry. Prigozhin was killed in a plane crash in Russia last week.
Russia also says it has deployed tactical nuclear weapons in Belarus.