British Foreign Secretary William Hague and Russian Foreign Minister Sergei Lavrov say they have agreed to increase pressure on Syria's government for the withdrawal of army tanks and artillery from residential neighborhoods across Syria.
The development at talks between Lavrov and Hague in Moscow follows the May 25 massacre of 108 people -- mostly women and children -- in the Syrian village of Houla.
The United Nations-Arab League special envoy on Syria, Kofi Annan, has meanwhile arrived in Damascus a day ahead of planned talks with President Bashar al-Assad. Annan called for Assad to "take bold steps" that signal a serious intention to resolve the crisis peacefully -- and to "help create the right context for a credible political process."
In Moscow, Lavrov said the most important diplomatic step in the Syrian crisis is to work to implement Annan's six-point peace plan -- which required Damascus to remove army tanks and artillery from urban residential neighborhoods by April 10.
Lavrov, however, stopped short of Backing Britain's calls for Syrian President Bashar al-Assad to step down from power.
"For us, it is not important who is in power in Syria, whatever kind of regime they have," Lavrov said. "The main thing for us is, first of all, an end to all violence, making sure no more people die -- and first of all, the civilian population -- and to ensure a political dialogue within which Syrians themselves can decide the fate of their country."
Lavrov also said both Syria's government and opposition fighters "clearly had a hand in the deaths of innocent people" in Houla, "including dozens of children."
Hague said Britain's calls for Assad to step down were "long-standing," but added that there is an "absolutely urgent priority" to have Annan's plan implemented and create "a more plural, democratic system" in Syria.
"Finding a solution to this involves him standing aside. But the important thing is that the Annan plan is pursued in whatever way it can be pursued by Kofi Annan meeting the six points," Hague said. "That is now the urgent priority. There are a variety of ways of doing that. But it certainly involves a political process."
In his remarks in Damascus, Annan said those responsible for the Houla attacks -- which he called "brutal crimes" -- must be held accountable. Annan repeated calls for all forces in Syria to lay down their arms to permit the six-point plan to be implemented.
"This message of peace is not only for the government but for everyone -- every individual with a gun," Annan said. "The six-point plan must be implemented comprehensively, and this is not happening today."
Annan said he planned to have "serious and frank discussions" with Assad. He also said he was "horrified" by the May 25 massacre.
On May 27, UN monitors reported to the Security Council that 49 children and 34 women were among those killed in Houla. They say most were killed by artillery or tank shells that only Syrian government forces possess.
The Security Council statement was read out by Azerbaijan's Deputy UN Ambassador Tofig Musayev.
"The members of the Security Council condemned in the strongest possible terms the killings -- confirmed by United Nations observers -- of dozens of men, women, and children and the wounding of hundreds more in the village of [Houla], near Homs, in attacks that involved a series of government artillery and tank shellings on a residential neighborhood," Musayev said.
Syria's UN envoy Bashar Jaafari said accusations of government responsibility were part of a "tsunami of lies" against Damascus, which has blamed "terrorists" for the massacre.
In Damascus, Syrian Foreign Minister spokesman Jihad al-Makdesi accused opposition fighters of carrying out the Houla massacre using recently obtained mortars and antitank missiles. He also announced an investigation by a Syrian military commission.
Human Rights Watch has called for UN experts to investigate the Houla massacre, saying there is "no way a Syrian military commission can credibly investigate this horrendous crime."
With reporting by AFP, AP, and Reuters