This is stated in the order of the head of state, published on the official portal of legal information.
"Accept the proposal of the Russian government ... on the creation of the Joint Regional Air Defense System of Russia and the Republic of Tajikistan," the document says.
Putin instructed the Ministry of Defense, with the participation of the Ministry of Foreign Affairs, to hold negotiations with Tajikistan and upon reaching an agreement to sign the said agreement on behalf of Russia, as well as to introduce into the draft approved by the Cabinet of Ministers "changes that are not of a fundamental nature."
In late April, Russian Defense Minister Sergei Shoigu, in talks with his Tajik counterpart Sherali Mirzo, announced that Russia and Tajikistan are creating a joint air defense system.