Amid a cease-fire repeatedly marred by violence, Syria's government and the United Nations have agreed on a plan for implementing the peace agreement brokered by U.N.-Arab League envoy Kofi Annan.

A spokesman for Mr. Annan said Thursday the agreement outlines the role of an advance team of observers in Syria as well as provisions for monitoring the week-old cease-fire between government and opposition forces.

The spokesman says mediators are holding talks with opposition representatives on a similar agreement.

Earlier, U.N. Secretary-General Ban Ki-moon said Syria has yet to fully implement the cease-fire deal, but he is calling on the U.N. Security Council to authorize a three-month mission. He has proposed a 300-member observer mission that would be deployed to approximately 10 locations in Syria.

A small advance team of monitors began work in Syria this week.

Mr. Annan's deputy and the deputy head of the U.N. peacekeeping department are scheduled to brief the Security Council Thursday morning.

Meanwhile, rights activists say Syrian government troops and army defectors clashed in the eastern city of Deir el-Zour on Thursday. The Britain-based Syrian Observatory for Human Rights says the fighting left one person dead and several injured. The group also reports a bombing in the city of Homs.

U.S. Secretary of State Hillary Clinton will join Arab and European foreign ministers attending a “Friends of Syria” meeting in Paris on Thursday.

On Wednesday, Clinton said the situation in Syria is at a “critical turning point.”

“Either we succeed in pushing forward with Kofi Annan's plan in accordance with the Security Council direction with the help of monitors, steadily broadening and deepening a zone of non-conflict and peace, or we see [Syrian President] Assad squandering his last chance before additional measures have to be considered.”

The head of the opposition Syrian National Council, Burhan Ghalioun, said the “Friends of Syria” meeting is important as the international community continues to look at using sanctions to pressure Syrian President Bashar al-Assad, but that other measures, including protecting civilians, are still needed.

“I think we need to go back to the idea of protecting the civilians. It was done in Kosovo and elsewhere. There is no reason why after 14 months of organized, collective and systematic killings that the international community is not looking at a plan that could help people to protect themselves.”

The U.N. says the crackdown in Syria has killed more than 9,000 people since March 2011.