YEREVAN -- Russian President Dmitry Medvedev and his Armenian counterpart, Serzh Sarkisian, have signed a deal extending Moscow's lease of a military base in the South Caucasus country by 24 years.
Moscow had been set to vacate the Gyumri base in western Armenia in 2020. But the new deal extends the lease until 2044, and commits Russia to updating Armenia's military hardware and ensuring both countries' security, together with Armenian armed forces.
At a news conference following the August 20 signing in Yerevan, Sarkisian praised the deal, which he said would expand the sphere of Russia's "geographic and strategic" responsibilities.
"The Russian side has made a commitment to ensure the military security of the Republic of Armenia and to cooperate in equipping our armed forces with advanced weaponry," Sarkisian said.
The new deal, updating a 1995 treaty, appears to cement Russia's already-strong presence in Armenia. Yerevan has been Moscow's only reliable ally in the South Caucasus, a region where Georgia and Azerbaijan have proved more irascible, independent-minded neighbors.
Armenian officials have been quick to tie the deal to their long-standing dispute with Azerbaijan over Nagorno-Karabakh, the Armenian-majority enclave at the center of a six-year war between the two countries that ended with an uneasy cease-fire in 1994.
Azerbaijan, which has used its massive energy wealth to build up its military strength, has frequently suggested it is preparing to resolve the outstanding dispute by force.
Armenian officials say the new Russian deal -- with its guarantee of Armenian security -- would prevent such an outcome. It is unclear, however, that the pledge from Moscow would extend to Nagorno-Karabakh, which is located within Azerbaijan's borders.
Medvedev said Russia sought to play the role of peacemaker in the region, and that Moscow would stress negotiations as the best channel for resolving Nagorno-Karabakh.
"The task of the Russian Federation as the largest state in the region, the most powerful state economically and militarily and in terms of its capacity to ensure security, is to maintain peace and order," Medvedev said.
Elkhan Polukhov, a spokesman for Azerbaijan's Foreign Ministry, called on Moscow to honor previous agreements on not using arms at the Gyumri base against Azerbaijan.
The Gyumri base is equipped with arms and other resources transferred from two shuttered Russian bases in Georgia. Polukhov said that according to the terms of the transfer, Moscow had pledged it would not use the relocated arms and equipment against Azerbaijan.
Russia has sought to downplay the significance of the new defense pact. Speaking earlier this week on Armenian television, Foreign Minister Sergei Lavrov said no change should be expected in the functions of the Gyumri base.
Lavrov also failed to deny reports that Moscow has sold S-300 antiaircraft systems to Armenian rival Azerbaijan, saying only that Russia never supplied arms to regions "where such supplies may destabilize the situation."
It is not clear what military upgrades Moscow will provide for Armenia. The Gyumri base currently houses MiG-29 fighter jets and S-300 missile systems, as well as some 5,000 troops.
Russian Defense Minister Anatoly Serdyukov, speaking on August 20 in Yerevan, said his country had no immediate plans to lease additional S-300 systems to Armenia.
Opposition politicians in Armenia have warned that Russia's rumored arms sales to Azerbaijan will disturb the region's delicate balance of military power and leave Armenia at a distinct disadvantage if the Nagorno-Karabakh conflict escalates into a new war.
Other observers have suggested the move is meant to solidify Russia's military foothold in the region as a warning to larger neighbors like Iran and Turkey. Gyumri, Armenia's second-largest city, is just 20 kilometers from the Turkish border.
The signing included broader talks about strengthening bilateral ties, with Armenia awarding Russia a contract to build two new nuclear reactors at a Soviet-era nuclear power plant.
Later on August 20, Medvedev and Sarkisian are set to attend an informal meeting of the Collective Security Treaty Organization, which groups Armenia, Belarus, Kazakhstan, Kyrgyzstan, Russia, Tajikistan, and Uzbekistan.
written by Daisy Sindelar in Prague with reporting from Yerevan by RFE/RL's Armenian Service and agency material