"The gaps between the parties are so wide that only the kind of concerted international pressure we're seeing here
has a chance of working," said a Western diplomat who is closely involved in the talks and requested anonymity, Reuters (Estelle Shirbon) reported:
"The message to them is very clear now: There is no political way out of the Chida Hotel without a deal," he said, referring to a small hotel on the outskirts of the Nigerian capital Abuja where the talks are taking place.
Observers say a collapse of the Abuja talks would be disastrous.
"The scenario of failure is very scary. You can be sure that the government would go after these guys (the rebels)," said one Western diplomat, adding that parties who block a deal would likely face U.N. sanctions.
Zoellick's team, along with Britain's International Development Secretary Hilary Benn and a host of European Union and Canadian diplomats, shuttled between government and rebel delegations.
Nigerian President Olusegun Obasanjo and Congo Republic Denis Sassou Nguesso, who is also chairman of the AU, were due to meet with the two sides and mediators in the evening to ratchet up pressure for a deal.
A senior AU source said this would take hours and the midnight deadline was likely to slip but only for discussions to continue late into the night.
"The clock will stop at midnight but this is it, there is no extension," he said.