The Russian Foreign Ministry said in a statement that the two senior diplomats welcomed "the implementation of the ceasefire" in the Arab country.
The duo also talked about the outlook for resuming the UN-backed peace talks on ending the conflict in Syria.
The two top diplomats also discussed ways for making sure that the truce is fully upheld, “including enhancing military cooperation between Russia and the United States.”
Earlier on Saturday, the Russian military said the air force has halted all combat sorties in Syria to help secure the ceasefire and avoid any “bombing mistakes.”
The ceasefire agreement in Syria entered into force at midnight amid Saturday hopes the truce would lead to an end of nearly five years of war.
Damascus also accepted the terms of the truce on the condition that military efforts against the Takfiri Daesh and the al-Nusra Front terrorists, who are not included in the ceasefire agreement, continue, Press TV reported.
Staffan de Mistura, the UN special envoy for Syria, said he plans to resume indirect peace talks between the Syrian government and opposition on March 7 on the condition that the two sides observe the ceasefire.
He announced a halt in the peace talks on February 3, after the foreign-backed opposition refused to continue the discussions in the wake of Syrian army gains.
The foreign-sponsored conflict in Syria, which started in March 2011, has claimed the lives of some 470,000 people and left 1.9 million injured, according to the Syrian Center for Policy Research.