RIYADH: Nigerian President Umaru Yar'Adua is "doing fine" as he recuperates after treatment at a Saudi hospital and is awaiting his doctor's approval to return home, the country's ambassador said on Saturday.

"President Yar'Adua is doing fine now; he is eating and resting," ambassador Abdullah Aminchi told AFP by telephone.

The Nigerian leader is staying in VIP quarters attached to the King Faisal Specialist Hospital in Jeddah where he took treatment.

Aminchi said it was not yet possible to say when he could return to Nigeria. "It depends on his doctors," he said.

Yar'Adua was admitted for treatment for a heart-related ailment in the Saudi Red Sea city hospital on November 23.

His absence and long silence until a brief interview with the BBC last week has left Africa's most populous country in an administrative vacuum.

The Federal High Court in Abuja ruled on Wednesday that Vice President Goodluck Jonathan could carry out the president's functions in his absence, but could not become acting president.

But opposition lawyers have petitioned courts to force Yar'Adua to install his deputy as acting president until he is well enough to return.