The Quartet on the Middle East, which includes Russia, the United States, the European Union and the United Nations, will hold its next meeting on Monday, the United Nations said. "Heads of the quartet’s delegations will meet in the conference hall of UN Secretary-General Ban Ki-moon in the UN’s headquarters" in New York, UN Secretary General Ban Ki-moon’s press service said. No agenda was voiced for the meeting, the first since September, which Russian Foreign Minister Sergei Lavrov is expected to attend along with his Western colleagues, Russia's News Agency (RIA Novosti) reported. The Quartet on the Middle East is an unofficial group established in 2002 and devoted to negotiating peace in the Israeli-Palestinian conflict. Tensions escalated in the conflict zone since Friday, with sides trading off rocket attacks and airstrikes.