Mr Abiola, whom unofficial results gave as the winner over Bashir Othman Tofa, candidate for the conservative National Republican Convention, told a press conference he was following the people's will.
Nigeria's military dictatorship accused the United States and Britain of inciting Nigerians against the government after the two countries imposed sanctions in protest against the regime's annulment of the elections.
Britain announced it was suspending training courses for Nigerian officers, withdrawing its military advisory team from the country and reviewing all new aid commitments. Washington cut off dollars 450,000 (pounds 300,000) in aid for training Nigerian soldiers.
In a harshly-worded statement released through the office of the number two in the military regime, Admiral Augustus Aikhomu, the government led by General Ibrahim Babangida referred to its two biggest trading partners as 'the enemy' and accused them of trying to destabilise the country. 'The federal government has unearthed a plot by the governments of the United States and Britain not only to mobilise their European allies against Nigeria but also to incite peace-loving Nigerians against themselves and their government, and incite sections of the armed forces against the government,' the statement said.
Leading Nigerians expressed outrage at the military government's decision. Wole Soyinka, the Nobel prize winner, joined other prominent Nigerians in condemning the military regime. Chief Emeka Anyaoku, the Commonwealth Secretary-General, called on the Nigerian leadership to 'pull the nation back from the brink to which it is being driven by these events'. In Lagos the Campaign for Democracy, an umbrella group of about 40 organisations advocating a return to democracy, has called for a campaign of civil disobedience.
In London, the Prime Minister, John Major, sent a message to General Babangida expressing concern at the developments. The Nigerian High Commissioner, Alhaji Abubakar Alhaji, was summoned to the Foreign Office and told of Britain's displeasure by Baroness Chalker, Minister for Overseas Development.