By Lesley Wroughton and Michael Shields
VIENNA (Reuters) - The presidents of Armenia and Azerbaijan agreed on Monday on the need for a ceasefire and a peaceful settlement to the conflict in breakaway Nagorno-Karabakh, according to a joint statement by the United States, France and Russia.
The two leaders also agreed at a meeting in Vienna they would fix the time and place of their next meeting in June and that the Organisation for Security and Cooperation in Europe (OSCE) would quickly finalize a plan to monitor the ceasefire in Nagorno-Karabakh, the statement said.
"The presidents reiterated their commitment to the ceasefire and the peaceful settlement of the conflict," it said. "To reduce the risk of further violence, they agreed to finalize in the shortest possible time an OSCE investigative mechanism."
The Vienna meeting was the first between Armenian President Serzh Sarksyan and Azeri President Ilham Aliyev since a dramatic flare-up in violence between Armenian-backed separatists in Nagorno-Karabakh and Azeri forces last month which killed dozens of people and pushed relations to a multi-year low.
The existing ceasefire may have stopped the short conflict becoming an all-out war a month ago, but gunfire and shelling still echo nightly, residents say, and people are still being killed.
After the meeting, Russian Foreign Minister Sergei Lavrov said he sensed there was now a desire on both sides for a compromise and that Russia was ready to do what it could to broker a more satisfactory deal, according to RIA news agency.
U.S. Secretary of State John Kerry, in Vienna for meetings on Syria and Libya, held one-on-one talks with each of the leaders.
Sarksyan's office confirmed the details in a statement, saying a deal had been struck to step up monitoring of the existing ceasefire, to look at beefing up the OSCE team and to take steps toward resuming talks on finding a more permanent solution.
The conflict has worried the international community in part because it could cause instability in a region that serves as a corridor for pipelines taking oil and gas to world markets.
The United States said before the meeting it was seeking a commitment from both leaders to a 1994 ceasefire agreement and confidence building measures that could eventually lead to a comprehensive settlement.
A U.S. official said the meeting would not have time to delve into the substance of how the conflict could be resolved, although it would seek support from both sides of elements that would form the basis for moving ahead.
The ex-Soviet state of Azerbaijan and separatists backed by Armenia fought a war over the territory of Nagorno-Karabakh in the early 1990s with thousands killed on both sides and hundreds of thousands displaced.
The war ended with a truce in 1994, although there has been sporadic violence since. The ceasefire was shattered last month when Azerbaijan's army and Armenian-backed separatists exchanged heavy fire using artillery, tanks, rockets and helicopters.
(Additional reporting by Andrew Osborn and Polina Devitt in Moscow and Hasmik Mkrtchyan in Yerevan.; Editing by Gareth Jones and Cynthia Osterman)