Russia's Foreign Minister Sergei Lavrov and the US Secretary of State John Kerry are to discuss the situation in Nagorno-Karabakh, Syria and Ukraine, the Russian Deputy Foreign Minister Sergei Ryabkov told RIA Novosti.

The discussions will be held in Vienna on May 16.

"Today, Syria and Nagorno-Karabakh, as well as Ukraine and bilateral relations are the main topics," added Ryabkov.

Earlier, Lavrov said he intends to hold a meeting with Kerry in Vienna on May 16.

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.