The presidents issued a joint statement deploring the situation in Togo, where Gnassingbe seized power with the backing of the armed forces following the death in office of his father, Gnassingbe Eyadema on 5 February.
They ordered the Togolese government representatives to attend a summit in Niamey, the capital of Niger on Saturday.
If the Togolese authorities failed to attend this meeting, the Economic Community of West African States (ECOWAS) would impose immediate sanctions on Togo, the presidents of Nigeria, Niger, Ghana, Benin and Mali added.
The Togolese government meanwhile took steps to try and close down five private radio stations and two independent television stations in Lome, alleging that they were in arrears with tax payments, journalists on the affected stations said.
However, large crowds of angry people formed outside Kanal FM and Radio Nostalgie, preventing the police from moving in to shut them down, the journalists told IRIN. Similar situations were reported at the other independent broadcasters targeted by the authorities, they added.
Earlier in the day, police used tear gas to disperse a demonstration by several hundred people in Lome against Gnassingbe's seizure of power.
The presidents of ECOWAS member states Nigeria, Niger, Ghana, Benin and Mali assembled on Friday morning in Cotonou, the capital of neighbouring Benin, for preliminary talks in the airport's VIP lounge.
But Benin government sources said their plans to fly on together for a meeting with Gnassingbe in Togo fell through after Nigerian President Olusegun Obasanjo insisted that the encounter take place in Lome.
Gnassingbe switched the talks venue from Lome to Kara on Thursday and prevented a Nigerian plane carrying an advance party of Obasanjo's aides from landing in the Togolese capital.
This angered Obasanjo, who initially announced that he was cancelling plans to fly to Togo as part of the ECOWAS mission.
Officials in the Nigerian capital Abuja said on Friday morning that Obasanjo had relented after receiving an apology from the Togolese government.
But officials in Benin said Gnassingbe's insistence that the talks take place in Kara, his father's birth place, 400 km north of the capital, made Obasanjo dig his heels in and refuse to go.
Ultimatum
Following the break-up of the ECOWAS mini-summit at Cotonou airport, Benin's Foreign Minister, Rogatien Biaou, read out a joint communique.
This deplored the situation in Togo and set an ultimatum for the authorities there to attend a meeting with President Mamadou Tandja of Niger, the ECOWAS chairman, in Niamey within 24 hours.
"The heads of state have invited the Togolese authorities to Niamey to meet Mr Tandja, the current president of ECOWAS, tomorrow, Saturday," the statement said. "If they do not attend the meeting they risk immediate sanctions."
Biaou said these would be imposed for breaching the conditions of democracy and good governance set out in article 45 of the ECOWAS charter.
They would include Togo's suspension from ECOWAS, the refusal of the organisation's 14 other member states to support Togo in international forums and the refusal of ECOWAS governments to send delegates to international meetings held in Togo.
The purpose of the aborted ECOWAS mission had been to persuade Gnassingbe to respect Togo's constitution as it stood before he made retroactive changes to it to legitimise his seizure of power.
The constitution as it stood before parliament amended sections of the document on Sunday, called for the leader of the National Assembly to take over as interim head of state and for presidential elections to be held within 60 days.
Mohamed Ibn Chambas, the Executive Secretary of ECOWAS, told reporters on his return to ECOWAS headquarters in Abuja that the heads of state had refused to go to Kara to avoid giving any form of legitimacy to Gnassingbe.
Meanwhile, in Lome, police used tear gas and batons on Friday to break up a protest demonstration against the de facto father-to-son succession.
A few hours later, government officials accompanied by police armed with automatic weapons tried to shut down most of the private radio and television stations in Lome, saying they were behind on tax payments.
An angry crowd of Lome residents prevented officials from shutting Kanal FM, which remained on air and another, of about 1,000 people formed soon afterwards outside Radio Nostalgie and its sister television station TV7.
Journalists at Radio Nostalgie said a group of armed paramilitary gendarmes came to the scene, but kept their distance from the crowd and did not try to intervene
Earlier in the day, a group of government officials, accompanied by two policemen, tried to close down Radio Nostalgie, but they were persuaded to go away and get a judicial warrant before doing so.
On Thursday the government shut down a private radio station in the nearby coastal town of Aneho after it broadcast an interview with Harry Olympio, a former government minister who has been calling on Togo's five million people to resist Gnassingbe's takeover.
Supporters of Olympio, a distant cousin of exiled opposition leader Gilchrist Olympio, staged the demonstration in Lome on Friday that was broken up by police.
A broad coalition of opposition groups has called for a separate protest march in the capital on Saturday in defiance of a two-month ban on public demonstrations imposed by the authorities.