During the call, Obama welcomed that an understanding was reached between the US, Russia, as well as other partners in the International Syria Support Group on the terms and modalities for such a cessation of hostilities in the war-torn country from February 27.
"Obama emphasised that the priority now was to ensure positive responses by the Syrian regime and armed opposition as well as faithful implementation by all parties in order to alleviate the suffering of the Syrian people, galvanise UN-led political process, and focus on defeating ISIL," the White House said.
Obama underscored the importance of quickly reaching agreement on modalities for holding free and fair elections in eastern Ukraine that meet OSCE standards, the White House said.
In a landmark announcement, the US and Russia today said that the Syria ceasefire would begin at midnight Damascus time (2200 GMT Friday) and would apply to parties to the conflict that have committed to the deal - but not to the Islamic State group or Al-Nusra Front, an Al-Qaeda affiliate.