The United Nations Security Council voted unanimously in support of a planned cease-fire in Syria Friday, calling on the "hostilities" to stop.

The U.S. and Russia drafted the plan, which U.S. Ambassador Samantha Power said included "practical, concrete steps... to reduce the violence and create space for a long-overdue political transition." She admitted that the cease-fire would not include terror groups such as the Islamic State.

It was set to take effect at 5 p.m. local time Friday in New York, midnight in Syria. Peace talks would resume March 7 if the cease-fire "largely holds," according to Staffan de Mistura, U.N. Special Envoy for Syria.

If the cessation of hostilities holds, it would mark the first time international negotiations have managed a pause in Syria's five-year civil war.

The draft resolution calls on the warring sides to grant access to aid workers to enable them to address the humanitarian crisis in the country, especially in besieged areas where civilians are in desperate need of supplies.

The resolution also urges the government of Syria and the Syrian opposition “to engage in good faith in these negotiations.” 

For the cease-fire to succeed, multiple armed factions will have to adhere to its terms.

The Syrian government and a leading opposition bloc have agreed to the cessation of hostilities, but the accord excludes U.N.-designated terrorist groups like the Islamic State and Nusra Front, which hold swaths of Syrian territory.

Warplanes on Friday continued to launch airstrikes against rebel-held positions in the suburbs of the Syrian capital and near the northern city of Aleppo. A spokesman for the U.N. secretary-general acknowledged "an increase of military activity across the board in Syria" in the hours leading up to the cease-fire.

"It's tragic but unfortunately not surprising," Stephane Dujarric said, adding: "The only thing that is required is for people to take their fingers off the trigger."

Fox News' Jonathan Wachtel and The Associated Press contributed to this report.