The United States on Monday suspended negotiations with Russia over bilateral engagement in Syria due to Moscow’s continued assault on the besieged city of Aleppo, according to the State Department.
"The United States is suspending its participation in bilateral channels with Russia that were established to sustain the cessation of hostilities," State Department spokesman John Kirby said in a statement.
The decision comes five days after Secretary of State John Kerry threatened to pause talks with Russia intended to restore a ceasefire agreement.
The week-long deal implemented on Sept. 9 fell apart after violence erupted between rebel forces and the Syrian military in rebel-held territories of Aleppo. An estimated 275,000 civilians are still trapped in the northern Syrian city with hundreds of people killed within the past week, according to the New York Times.
"This is not a decision that was taken lightly," Kirby said. "The United States spared no effort in negotiating and attempting to implement an arrangement with Russia aimed at reducing violence, providing unhindered humanitarian access, and degrading terrorist organizations operating in Syria."
The U.S. has also halted plans for joint airstrikes against the Islamic State and the al Qaeda-linked Nusra Front.
"Unfortunately, Russia failed to live up to its own commitments," Kirby continued. "Russia and the Syrian regime have chosen to pursue a military course, inconsistent with the cessation of hostilities, as demonstrated by their intensified attacks against civilian areas, targeting of critical infrastructure such as hospitals, and preventing humanitarian aid from reaching civilians in need."
Sergei Ryabkov, the deputy foreign minister of Russia, told reporters last week he had suggested 48-hour cessations of violence to allow humanitarian access, but the U.S. refused. He said a seven-day pause would give terrorist groups enough time to take necessary measures to replenish supplies and regroup forces.
Despite multiple failed attempts, the United Nations Security Council began negotiations Monday on a draft resolution intended to persuade the U.S. and Russia to implement a truce in Aleppo to "put an end to all military flights over the city," Reuters reported.