United Nations envoy Lakhdar Brahimi met with top U.S. and Russian envoys on Thursday in a bid to save the faltering Syrian peace talks from collapse. Brahimi says he won pledges from both sides to push for a breakthrough between the Assad regime and Syrian rebels, but declined to offer specifics.

Lakhdar Brahimi: “They have kindly reaffirmed their support for what we are trying to do and promised that they will help both here and in their capitals and elsewhere to unblock the situation for us, because until now we are not making much progress in this process.”

Human rights activists say Syria has endured its deadliest violence so far in the three weeks since peace talks began, with an average of 236 people killed per day.