US President Barack Obama recognized Russia’s efforts at mediating the Nagorno-Karabakh conflict in a phone conversation with Russian President Vladimir Putin, the Kremlin’s press service said Wednesday, Sputnik reports.

Putin briefed Obama as the head of state that co-chairs an international settlement group with Russia and France on the outcome of last month's trilateral talks in St. Petersburg between the sides to the conflict, Azerbaijan and Armenia, the Kremlin said.

“Vladimir Putin stressed that, in organizing the negotiations, Russia proceeded from the need to promote the speedy stabilization of the situation in the conflict zone and the creation of conditions to advance the peace process. Barack Obama praised Russia’s efforts,” the Kremlin added.

The conflict between the two South Caucasus countries began in 1988 when Armenia made territorial claims against Azerbaijan. As a result of the ensuing war, in 1992 Armenian armed forces occupied 20 percent of Azerbaijan, including the Nagorno-Karabakh region and seven surrounding districts. The 1994 ceasefire agreement was followed by peace negotiations.

Armenia has not yet implemented four UN Security Council resolutions on withdrawal of its armed forces from the Nagorno-Karabakh and the surrounding districts.