Hourmadji Moussa Doumgor, the communications minister, said Chad would shut down its oil production at the end of April if its Citibank account in London, which contains millions in oil revenue, remains frozen.

On Friday, the government set April 18 as the date for turning off the taps over the row, which began in January when the World Bank first suspended aid, then had the Citibank account frozen, as punishment for Chad's sidestepping of strict rules on how it spends its oil revenues.

Doumgour said Sunday's postponement was in response to a request from the United States, which it said had offered to mediate in the standoff.

US mediation

"The Chadian government has decided to wait to turn off the taps until the end of American mediation," he said.

"The prime minister met with the US ambassador ... to announce that the government gives a favourable reception to the offer of mediation from the American government, and that it has decided to give more time for mediation according to the timetable set out by the US State Department - that is to say, until the end of April."

Doumgour said that a US undersecretary of state was expected next week to begin mediation efforts.

The landlocked north-central African country's economic prospects were transformed with the discovery of oil in 1993, which it has been producing since October 2003, routing it to a Cameroonian port through a pipeline.