Russian Foreign Minister Sergei Lavrov and US Secretary of State John Kerry have welcomed "the implementation of the ceasefire in Syria," the Russian foreign ministry said in a statement on Saturday.

In a telephone call the ministers "also discussed the outlook for resuming the peace negotiation process in the framework of the International Syria Support Group (ISSG)," the ministry added.

Both sides recognised the "particular importance" of working together as co-chairs of the 17-nation ISSG. The US State Department spokesman John Kirby said Kerry had welcomed the "constructive engagement" among members of the ISSG, "as parties continue to closely monitor and assess reports from the field."

In the telephone call, "They agreed that while initial reports have been encouraging, a serious effort by all parties will be critical to success going forward," Kirby added.

Lavrov and Kerry also discussed "ways for ensuring it (the ceasefire) is fully upheld, including enhancing military cooperation between Russia and the United States," the Moscow statement said.

Steinmeier hopeful of truce

German Foreign Minister Frank-Walter Steinmeier told the 'Welt am Sonntag' newspaper he was hopeful of the effects of the ceasefire: "The ceasefire was not agreed immediately, everywhere with 100 percent compliance," he said. "But for the first time there is a chance of a real respite."

With every hour that the truce holds, "the hope of peace in Syria rises for millions of Syrian people, not only in the country itself but also for those who have fled war and terror."

The first major truce in the five-year civil war began at midnight (2200 UTC) in Syria on Friday night. It called for a cessation of hostilities between the forces of Russian-backed President Bashar al-Assad and nearly one hundred opposition groups. It does not cover the self-declared Islamic State (IS) and Al-Nusra Front, which is linked to al-Qaeda.

The United Nations envoy Staffan de Mistura has said peace talks are to resume on March 7 if the ceasefire prevails and more aid is delivered to Syrian communities.

jm/jr (AFP, dpa)