After days of carnage in the northern Syrian city of Aleppo, the United States and Russia have persuaded the Syrian government and rebels to extend a truce to cover the city, the Associated Press reported Wednesday. 

The agreement comes after fears the ceasefire agreed to between Moscow and Washington in February was starting to fall apart. However, a major question remains over the long-term durability and sustainability of the truce, which does not apply to the Islamic State group or the Nusra Front, both militant organizations pitted against the Syrian government.

“It is critical that Russia redouble its efforts to influence the regime to abide by fully,” U.S. State Department spokesman Mark Toner said. “The United States will do its part with the opposition.”

The truce was reached late Tuesday and officially went into effect Wednesday. U.S. Secretary of State John Kerry said it would take a few days for commanders in the field to be notified of the truce.

Both the U.S. and Russia are expected to monitor the truce, which was originally envisioned as a nationwide effort that has now splintered into commitments for specific cities, including recommitments to truces in Latakia and Damascus that were discussed this week.

“We have seen an overall decrease in violence in these areas, even though there have been reports of continued fighting in some locations,” Toner said in a State Department statement.

Aleppo, Syria’s largest city, has struggled through intense violence for nearly two weeks as diplomats have worked to rebuild the February truce. Approximately 300 people have died during that time, with hospitals and civilian buildings hit.

Syrian President Bashar Assad has been a longtime Russian ally, and Western governments have repeatedly accused the Kremlin of targeting its airstrikes to prop up the leader. Russia began its airstrikes at the end of September. The five-year Syrian civil war has taken the lives of over 270,000 people and displaced millions, triggering a refugee crisis.