"The opposition delegation has regularly demonstrated that they are willing to engage constructively in the interests of all the Syrian people," Kerry said.
"In sharp contrast, we have seen a refusal to engage on the part of the regime," he said in a statement a day after the second round of peace talks in Geneva, Switzerland, between the Assad regime and the Western-backed opposition ended with no agreement on how to resolve the nearly 3-year-old conflict and no date for when a third round would start.
Kerry blamed the regime of President Bashar Assad for hindering progress while escalating bloodshed.
"While it stalled in Geneva, the regime intensified its barbaric assault on its civilian population with barrel bombs and starvation," he said. "It has even gone as far as to add some of the opposition delegates at Geneva to a terrorist list and seize their assets. This is reprehensible."
In contrast, the opposition "put forward a viable and well-reasoned road map for the creation of a transitional governing body and a viable path by which to move the negotiations forward," said Kerry, who was to fly Monday to the United Arab Emirates, a Persian Gulf country that supports the rebels.
Syrian Foreign Minister Walid al-Muallem told the official Syrian Arab News Agency the United States was to blame for the talks' failure, alleging it sought to "create a very negative climate for dialogue."
Damascus also said the opposition refused to abide by 2012's so-called Geneva I communique, which calls for the ending of violence.
The communique also calls for a political transition in Syria.
U.N. special envoy Lakhdar Brahimi, who mediated the talks, apologized to the Syrian people Saturday after the talks broke off.
He also questioned the value of continuing them.
"It's not good for Syria that we come back for another round and fall in the same trap that we have been struggling with this week and most of the first round," Brahimi said.
"So I think it is better that every side goes back and reflect and take their responsibility: Do they want this process to take place or not? I will do the same," he said.
The Britain-based Syrian Observatory for Human Rights said Saturday nearly 5,800 people were killed in Syria since the Geneva talks started Jan. 22.