US President Donald Trump has called for expanded co-operation with Russia as a ceasefire brokered by the two powers and Jordan for southern Syria came into effect.
The ceasefire covering three war-torn provinces is the first tangible outcome following months of strategy and diplomacy between the new Trump administration and Russian President Vladimir Putin.
Mr Trump tweeted that the ceasefire, which came into effect at noon on Sunday, “will save lives”.
“Now it is time to move forward in working constructively with Russia!” he posted on Twitter shortly after the agreement came into effect.
A resident and local opposition activist in Daraa, near the Jordanian border, reported calm when the truce began.
“There’s still a lot of anxiety,” said Ahmad al-Masalmeh. “We’ve entered the ceasefire but there are no mechanisms to enforce it. That’s what concerns people.”
Six years of fighting and siege have devastated Daraa, one of the first cities to see large protests against President Bashar Assad in 2011.
It remains contested by US-backed rebels and Syrian government forces supported by Russia and Iran. Large areas of the city have been reduced to rubble by government artillery and Russian air power.
The agreement followed weeks of secretive talks between the US, Russia and Jordan in Amman to address the build-up of Iranian-backed forces, in support of the Syrian government, near the Jordanian and Israeli borders.
Israel has repeatedly said it would not allow Iran, which is a close ally of the Syrian government, to set up a permanent presence in Syria. It has carried out a number of air strikes in Syria against suspected shipments of “game-changing” weapons bound for Hezbollah in Lebanon.
It has also struck Syrian military installations several times this year after shells landed inside the Israeli-controlled side of the Golan Heights.
Prime minister Benjamin Netanyahu said on Sunday that Israel would welcome a “genuine ceasefire” in southern Syria as long as it does not enable Tehran and its proxies to develop a military presence along the border.
The Trump administration has also ordered air strikes against the Syrian government and Iranian-backed militias, in a break with Obama administration policy.
The strikes, including one on a government air base in central Syria, drew only muted responses from Moscow.
No ceasefire has lasted long in the six-year Syrian war, and no mechanisms have been publicly set out to monitor or enforce this latest effort.
It was announced on Thursday on the sidelines of the G20 summit in Hamburg after a meeting between Mr Trump, Mr Putin and their top diplomats.
The Syrian government maintains it is fighting a war against terrorist groups. The al Qaida-linked Levant Liberation Committee is one of the most effective factions fighting alongside rebels in Daraa.
The truce covers the Quneitra, Daraa and Sweida provinces, where the government and rebels are also fighting Islamic State militants, who are not included in the agreement.