MOSCOW (Reuters) - Russia and the United States agreed on Tuesday to try to bring together Syria's warring parties at an international conference, possibly by the end of this month, in an attempt to negotiate an end to their civil war.
Foreign Minister Sergei Lavrov and Secretary of State John Kerry announced the agreement in Moscow, despite their nations' differences over Syria, saying they would work to ensure both the Damascus government and the rebels fighting it would attend.
The aim is to revive an agreement to create a transitional government that was reached in Geneva last June but was never put into force because it left open the question of what would happen to Syrian President Bashar al-Assad.
"The alternative (to a negotiated solution) is that there is even more violence. The alternative is that Syria heads closer to an abyss, if not over the abyss and into chaos," Kerry told a joint news conference with Lavrov.
"The alternative is that the humanitarian crisis will grow. The alternative is that there may be even a break up of Syria," said Kerry, who earlier held talks with Russian President Vladimir Putin in the Kremlin.
More than 70,000 people have been killed in more than two years of violence in Syria since the start of an uprising against Assad and his government.
Russia has been a staunch ally of Assad, blocking new sanctions against Syria at the United Nations and supplying the government with arms. But referring to Assad, Lavrov said Moscow was not concerned by the fate of particular individuals.
"The task now is to convince the government and all the opposition groups ... to sit at the negotiating table," he said.
"At the conference that we are proposing to convene, Russia and the United States consider it necessary to work with the aim of convincing representatives of both the government and the opposition to together determine how they can fully implement the Geneva Communique," Lavrov added.
Kerry said the conference should be held "as soon as is practical - possibly and hopefully by the end of the month". Neither said where it might take place.
Although the United States has said Assad must leave power, Kerry said the decision on who takes part in any transitional government should be left to the Syrians.
Both Russia and the United States have made clear that peace efforts have been stepped up because of growing concern that the violence could spread beyond Syria. Israel carried out air strikes against Syria twice over the weekend.
On April 25, the White House said U.S. intelligence agencies believe Syria has likely used chemical weapons against its own people, a view which if confirmed would mark a further escalation in the conflict.
Further, both the United States and Russia appear to be increasingly worried that Syria may end up dominated by Islamists, a possibility that could threaten U.S. ally Israel as well as fragile neighboring states such as Jordan and Lebanon.
Kerry said there would be "a growing crescendo of nations who will want to push for a peaceful resolution, rather than the chaos that comes with the break up of a country".
The government may have used chemical weapons has amplified calls for the United States to arm the rebels and talk about the possibility of U.S. military intervention, though Obama has made clear he has no desire to do this as he winds up the U.S. wars in Iraq and Afghanistan.
Kerry said the fate of U.S. legislation calling for the United States to arm the Syrian rebels would depend on any evidence on the use of chemical weapons in the conflict as well as on what progress is made towards a political resolution.
"So much will depend on what happens over the course of these next weeks as to what will happen to that particular legislation," he said. (Writing by Timothy Heritage and Arshad Mohammed; Editing by Steve Gutterman, Alison Williams and Cynthia Osterman)