The United States is to send a high-level delegation to Nigeria to urge the military leader, General Sani Abacha, to implement democratic reforms.

Announcing the mission, the State Department spokesman, James Rubin said the Nigerian leadership's current plans to hand control to a civilian government were flawed.

The spokesman said the American mission would leave within the next two weeks.

The BBC Washington correspondent says the move comes amid mounting concern in Washington about the run up to presidential elections in Nigeria, in which General Abacha is the sole candidate.