U.S., Russia Reach Ceasefire Deal In Southwest Syria, U.S. Official Says

WASHINGTON, July 7 (Reuters) - The United States, Russia and regional countries have reached a ceasefire deal in southwestern Syria, one of the combat zones in a six-year-old civil war, a U.S. official said on Friday.

U.S. Secretary of State Rex Tillerson was expected to provide more details of the deal to reporters in Hamburg, Germany, later on Friday, the official said.

Russia and Iran are the main international backers of Syrian President Bashar al-Assad while Washington supports some of the rebel groups fighting for his ouster. “Still a lot of work to be done,” the U.S. official said.

Jordan’s Petra news agency said the ceasefire would go into effect as of Sunday.

Tillerson has said the United States was prepared to discuss joint efforts with Russia to stabilizeSyria, including no-fly zones, ceasefire observers and coordinated deliveries of humanitarian assistance.

Tillerson was present at a meeting in Hamburg between U.S. President Donald Trump and Russian President Vladimir Putin, along with Russian Foreign Minister Sergei Lavrov.

The United States and Russia held secret talks on creating a “de-escalation zone” in southernSyria, Western diplomats and regional officials said in early June.

The proposed zone was in Deraa province, on the border with Jordan, and Quneitra, which borders the Israeli-occupied Golan Heights, they said.

The Syrian conflict has killed nearly half a million people, according to the Britain-based Syrian Observatory for Human Rights, and forced millions of others to flee the country.

Backed by Russian air power, Assad has regained ground in the last year that he lost to the mostly Sunni Muslim rebels earlier in the conflict.

The Syrian army has in recent months escalated its strikes in the southwestern city of Deraa in a campaign to reach the border with Jordan and wrest full control of the city.

The army said on Monday it would suspend combat operations in southern Syria, but rebels said the military had violated the ceasefire by striking areas under their control.

Separately, Russia, Turkey and Iran failed in talks on Wednesday to finalize an agreement on creating four de-escalation zones in Syria after Ankara raised objections.

The failure was seen as a setback for Moscow, the main architect of the plan, as it seeks to take the lead in global efforts to settle the Syrian war. The United States is only an observer in the so-called Astana process. (Writing by Alistair Bell; editing by Jeffrey Benkoe and Tom Brown)