Secretary of State John Kerry on Monday expressed hoped that a cease-fire in Syria brokered by the United States and Russia could still hold, despite a declaration from the Syrian military that the truce is over amid other indications the latest international attempt to quiet the fighting has failed.

Shortly after Syria's armed forces declared that the truce was dead and blamed opposition rebels for undermining it, Kerry noted that the cease-fire had not produced the desired reduction in violence and sustained delivery of humanitarian aid. But he said some aid was finally moving.

"We have not had seven days of calm and of delivery of humanitarian goods," Kerry told reporters on the sidelines of the U.N. General Assembly. Those seven days of calm and aid deliveries were required before the U.S. and Russia could embark on a plan to cooperate in targeting the Islamic State group and al-Qaida affiliates working in Syria.

He denounced the Syrian military declaration, but also suggested that Russia was partly to blame.

"It would be good if they didn't talk first to the press but if they talked to the people who are actually negotiating this," he said. "As I said yesterday, (it's) time to end the grandstanding and time to do the real work of delivering on the humanitarian goods that are necessary for access."

The Syrian military said in a statement Monday that "armed terrorist groups" repeatedly violated the cease-fire and took advantage of the truce to mobilize and arm themselves while attacking government-held areas. The statement said the rebels wasted a "real chance" to stop the bloodshed.

Before that announcement, Kerry had said the truce was "holding but fragile."

He said U.S. and Russian officials were meeting in Geneva to try to sort out aid deliveries to Aleppo and other besieged communities. American officials said, however, that conditions were still not right for U.S.-Russian military cooperation.

The truce took effect last Monday.

The United States, Russia, the Syrian government and the Syrian opposition have all traded allegations of truce violations.

A Syrian activist group said 92 people have been killed in Syria since the start of the cease-fire. The Britain-based Syrian Observatory for Human Rights said 29 children and teenagers were among those killed, as well as 17 women. The figure does not include dozens of Syrian soldiers and Islamic State militants killed in the eastern province of Deir el-Zour, the Observatory said Monday.

A mistaken air raid by the U.S.-led coalition also killed 62 Syrian soldiers.

The opposition reported 254 violations by government forces and their allies since the truce started on Sept. 12 and a senior Syrian opposition official declared the cease-fire "clinically dead."

Syrian state media said there were 32 violations by rebels on Sunday alone.