Russia on Thursday agreed to buy an advanced air defense system from U.N. member states for $1.5bn.
Russia said it was paying the $1bn in cash to join the alliance, which is under scrutiny in Europe over the downing of Malaysia Airlines flight MH17 in Ukraine in 2014.
The Russian Defense Ministry said in a statement that the system would be fitted to the TU-95, a long-range surface-to-air missile.
Russia has been pressing NATO member states to join it in a joint air defense shield, but those efforts have stalled over the Ukraine crisis.
The TU system, which could be fitted on TU launchers in Russia, will replace the existing Aegis system, the U.K.-based arms control group said.
Russian Prime Minister Dmitry Medvedev said in December he would buy an Aegis missile system from France, but France is in the process of purchasing two more of its own from France.
Russia’s Defense Ministry, which has been critical of NATO’s air defense capabilities, said in March it had ordered 12 TU missile systems, which would include four new launchers.
The United States is in talks to buy a fifth system from Russia for $2.8bn.
U.S.-based defense analysts say Moscow has long been wary of NATO and Western nations’ involvement in its military activities in Europe.