The two held talks in Geneva to try to find a way of reviving a cessation of hostilities that faltered months ago, according to BBC.
Kerry said they were close, but would not rush into an agreement.
The talks come as the Damascus suburb of Darayya was evacuated after a four-year siege by the government, BBC wrote.
After meeting for nearly 10 hours, Kerry said the "vast majority'' of technical discussions had been completed, adding that experts would remain in Geneva to work on the unresolved steps in the coming days, the report said.
He stressed that the only way to solve the conflict was through political agreement.
"We want to have something done that is effective and that works for the people of Syria, that makes the region more stable and secure, and that brings us to the table here in Geneva to find a political solution," he said.
Read alsoSyrian rebels advance south of Jarablus in Turkey-backed operationKerry also reminded journalists of the image, widely shared on social media, of a five-year-old boy sitting dazed in an ambulance after an air strike in Aleppo, saying "that image needs to motivate all of us, to get the job done".
