Russian President Vladimir Putin and South Ossetian President Leonid Tibilov signed the document after discussions of bilateral relations and coordination in the area of stability and security in the Caucasus region.
The treaty envisages the forming of a unified region of defense and security, freedom of movement between the two states, the integration of the customs bodies, expanding cooperation between the countries’ interior ministries, and several social issues.
South Ossetia, along with Abkhazia, broke away from Georgia in 1990, with Tbilisi declaring both occupied territories. Following Georgia's military campaign against the regions in August 2008, Moscow has recognized both entities as independent states.
Last month, South Ossetia and Russia established an official state border.
On Tuesday, US Department of State Spokeswoman Jen Psaki said Washington will not recognize the Russia-South Ossetia treaty.
Leonid Tibilov invited Vladimir Putin to the republic’s capital of Tskhinvali to celebrate its independence day on September 20.
“This year South Ossetia will celebrate its 25th anniversary of the founding of South Ossetia on September 20. I would like to invite you, Vladimir Vladimirovich [Putin] to this celebration,” Leonid Tibilov said after signing a cooperation and integration treaty with Putin in Moscow.