The head of West African bloc ECOWAS on Tuesday slammed attempts to compromise with Ivory Coast strongman Laurent Gbagbo, saying international solidarity against him had waned.

James Victor Gbeho also singled out South Africa for criticism over what he said was Pretoria's decision to send a warship to Ivory Coast. South Africa's ambassador here said it was a support vessel and had no military purpose.

The 15-member Economic Community of West African States (ECOWAS) has threatened to use force if Gbagbo does not step down.

"We find that others are encouraging Gbagbo not to yield ...," ECOWAS commission president Gbeho told journalists at a presentation by European Union observers on November's Ivory Coast election.

"The solidarity that started among us in the international community is fast being eroded."

Gbeho also said he was disappointed with moves on the crisis by the African Union.

Following a recent African Union summit, experts sent by an AU panel tasked with mediating peace in Ivory Coast met representatives of both sides in the crisis this week.

Asked if he was disappointed with the AU, Gbeho said, "yes, in a way, because there was the attempt to unravel what this region was doing.

"Any attempt to change the result that the Ivorian electorate have out of their own free will mandated, it's something that we should all regret, and I do hope that it will not come to that in the final analysis," he added.

Gbeho did not discuss details in his criticism of the South African vessel he said had been sent to Ivory Coast.

"As we talk now, there is a South African warship docked in Cote d'Ivoire," he said. "Action such as that can only complicate the matter further.

"I'm surprised that a distinguished country like South Africa would decide to send a frigate to Ivory Coast at this time."

South Africa's ambassador to Nigeria, Kingsley Mamabolo, said the vessel could be used as a neutral negotiating venue.

It had been docked in Ghana, which neighbours Ivory Coast, but he said he was unsure of its current location.

"There is nothing amiss about the vessel we sent," Mamabolo told AFP.

"It's just a harmless support vessel. It could be used for evacuation. It's not meant to go and intervene militarily."

He added that "South Africa in principle has never believed in intervention by force. We have always believed in negotiation to avoid unnecessary bloodshed."

South African President Jacob Zuma said last month that efforts to end the dispute by demanding "one of the two leaders must go" were not working and another way must be found.

Pretoria initially joined calls for Gbagbo to cede power, but Zuma appeared to backtrack in January, saying both candidates had raised "quite serious" allegations about voting irregularities.

ECOWAS, like much of the world, has recognised Gbagbo's rival Alassane Ouattara as president and demanded Gbagbo quit power.

However, the bloc faces difficulties in mustering troops for a military intervention.

Nigeria, likely to provide the bulk of any force, will hold elections in April and is seeking to stem unrest back home. Ghana, another ECOWAS member, opposes the use of force.

"The concern that some of us have is that apparently, because of certain geopolitical interests, some countries are keen on awarding a failure mark to ECOWAS heads of state," said Gbeho, who is from Ghana.

"They are saying that the whole matter should be looked at, that it seems Gbagbo was the winner, and if that is the situation then they must negotiate."

Gbeho said ECOWAS was not opposed to dialogue, but talks must end with Ouattara as head of state.

The EU observers presented their report in Abuja as they said they could not obtain fresh visas for Ivory Coast.

Their report, which recognised Ouattara as the victor and ruled out the need for a recount, had been presented in Brussels last month.