The Islamist terrorist group Boko Haram has stopped all talks with the Nigerian government, saying it could not trust a government of "unbelievers".

Abul Qaqa, a spokesman for the sect, said that it had "closed all possible doors of negotiations".

"Almighty God has told us repeatedly that the unbelievers will never respect the promises they made," Qaqa said. "As such, henceforth, we would never respect any proposal for dialogue."

Last week, the group said it was poised to stop bombing attacks and agree to a truce if the federal government releases all of its members being detained and nominates Sheik Ahmed Datti, president of the Supreme Council for Sharia in Nigeria, as mediator.

The negotiations were aimed at ending months of bombing and gun attacks by the sect in which hundreds have been killed, largely in the Muslim north of the country.

The group has said it wants to impose Islamic sharia law across the oil-rich country, inhabited by both Muslims and Christians.

Qaqa explained that a previous attempt to open a dialogue earlier this year ended with the arrest of one of Boko Haram's leaders in the northern city of Kaduna. "There was an initial meeting between us and the government and, in the process, one of our members, Abu Dardaa, was arrested in Kaduna," he said.

"Since then, we never trusted the government. However, following endless pleas by some notable Nigerians, whom we have enormous respect for, we resolved to give another chance," he said, adding that the second opportunity "was messed up".

Qaqa said the group is confident it will eventually dismantle the government and establish Islamic government in the African country.