Friday, July 3, 1998 Published at 17:47 GMT 18:47 UK
Commonwealth sets conditions for Nigeria
Chief Moshood Abiola: four years in detention
He said there also had to be free elections to produce a credible government.
Speculation that the remaining political prisoners will be freed shortly was boosted when Nigeria's highest ruling body, the Provisional Ruling Council, met to discuss visits by Chief Anyaoku and by the United Nations Secretary General, Kofi Annan.
Expectations at a peak
All major political decisions have to be ratified by the ruling council, which meets infrequently and only when essential.
The BBC Lagos correspondent says expectations are now at a peak among Nigerians that Chief Abiola's time in detention is soon to end.
'No further obstacles'
Mr Annan said Chief Abiola had agreed not to press his claim to the presidency - a condition set by the government for his release.
The BBC correspondent says that if the government believes this, there are no further obstacles to freeing him.
Chief Abiola's supporters have complained that any agreement he has made while in detention has been made under duress, and that once Chief Abiola is freed, he can do what he likes.
"If all the political prisoners are released and the correct things are done - well, it means a bright future for Nigeria," he said. "The correct things are that Abiola should be made the head of the government of national unity and reconciliation."
"I hope that when the release comes, it will be unconditional and [Abiola] will be able to participate in politics and run for election as he so chooses," Mr Annan said.
Mr Annan and Chief Emeka were allowed to visit Chief Abiola in a safe house in Abuja on Wednesday - the first independent international figures to see the detained leader in two years.
Quoting Chief Abiola, Mr Annan said that he was not naive enough to expect to leave prison and walk into the presidency.
US delegation to visit
The US State Department welcomed the agreement, which it said could be a key step in the transition to civilian government.
State Department Spokesman James Rubin said the American delegation would meet Nigeria's new leader, General Abdulsalam Abubakar, on Tuesday.