Russia blames US for delay in Syria ceasefire plan
Moscow's envoy appeared briefly in a Geneva hotel ballroom room set aside for a news conference to mark the end of talks with Kerry but did not mount the podium that had been prepared.
Instead, in a brief chat with reporters, he said in English: "I believe it is important for them to check with Washington. That's why I apologise for the delay. We cannot help it.
"It's going to be announced very soon I think. I hope before Washington goes to sleep, we can get some news. My appeal to you is to be patient. Same as me," he added.
Both Kerry and Lavrov had been expected to fly home later Friday, but all three officials said they still hoped to hold a news conference to announce the results of the negotiation.