Belarus joined the Shanghai Cooperation Organization (SCO) on July 4, Russian state-owned news agency TASS reported, citing Kazakh President Kassym-Jomart Tokayev.
"The admission of the Republic of Belarus to the Shanghai Cooperation Organization as a full-fledged member is now effective," Tokayev said after documents to admit the country as the organization's 10th member had been signed.
The SCO is an intergovernmental organization established by China and Russia in 2001 in Shanghai. It focuses on Eurasian political, economic, security, and defense issues.
Apart from Belarus, the organization includes China, India, Iran, Kazakhstan, Kyrgyzstan, Pakistan, Russia, Tajikistan, and Uzbekistan.
The SCO also has observer states and 14 dialogue partners.
Belarus has been a key ally to Moscow and supported Russian aggression against Ukraine but has not committed its own troops to fight directly in Russia's war.
The Belarusian military claimed that Ukraine is allegedly deploying its forces to the shared state border for potential "sabotage, terrorist acts," state-run news outlet Belta reported on June 29.
The Kyiv Independent could not verify the claim, while Belarusian state-run news outlets have a long history of unsubstantiated claims.
Russian forces launched the all-out invasion of Ukraine from Belarus in early 2022 but suffered a defeat near Kyiv and were forced to pull back.