India and Pakistan will join the Shanghai Cooperation Organization, a security group led by Russia and China and also including Central Asian republics, the organization said in a statement on July 10.
The group also offered the dialogue partner status to Azerbaijan, Armenia, Cambodia, and Nepal, the statement said.
It also said Belarus would obtain observer status, joining Afghanistan, Iran, and Mongolia.
The statement was released during a SCO summit in the Russian city of Ufa.
Russian President Vladimir Putin described the group's expansion as "a new stage in SCO development."
Russia sees the organization as a counterweight to Western alliances.
A day earlier, Ufa hosted a summit of BRICS nations -- Brazil, Russia, India, China, and South Africa.
The summits are widely seen as an attempt by Moscow to show it is not isolated despite its standoff with the West over Russia's role in Ukraine's conflict.
Moscow has deepened its ties with BRICS since being hit by Western sanctions over its 2014 annexation of Crimea and its support of pro-Russian separatists in eastern Ukraine.