Hopes of a last-minute deal to avert the fiscal cliff faded on Sunday when Senate leaders failed to meet a target for agreement and said they remained far apart on key issues.

Harry Reid, the Democratic Senate majority leader, and Mitch McConnell, who heads the Senate's Republican minority, emerged from closed-door talks shortly before 3pm to inform colleagues in the chamber they remained deadlocked.

McConnell said no single issue remained an "impossible sticking point" and blamed Democrats for not responding to a Republican offer made on Saturday evening.

"It's now 2pm and we've yet to receive a response to our good-faith offer. I'm concerned at the lack of urgency here."

He said he called vice-president Joe Biden, with whom he has worked before, to try to "jump start" negotiations. "I'm still willing to get this done but I need a dance partner."