The Gulf Co-operation Council (GCC) has halted its efforts to end the political crisis in Yemen after the country's president, Ali Abdullah Saleh, refused to sign a transition deal that would have seen him step down.

In a statement issued on Sunday, the GCC said it had suspended the initiative because of a failure to agree on suitable conditions.

Saleh attended a signing ceremony, in which the transition deal was ratified by members of his ruling party, but failed to add his signature to the document, saying he would not sign the deal unless opposition leaders were present.

Diplomats who had gathered for the ceremony in Sanaa, the Yemeni capital, were earlier evacuated from an embassy by helicopter after the building was surrounded by armed pro-government supporters.

Abdullatif al-Zayani, the secretary general of the GCC, "left without getting the signature of the president," Tareq al-Shami, the spokesman of Yemen's ruling General People's Congress, was quoted as saying.

The deal committed Saleh to stepping down within 30 days in return for immunity from prosecution. But, in a provocative statement on state television, Saleh warned of civil war if the opposition defied his call for them to be present at his palace to sign the deal.

"If they remain stubborn, we will confront them everywhere with all possible means," he said.

"If they don't bow, and want to take the country into a civil war, let them be responsible for it and for the blood that was shed and that will be shed if they insist on their stupidity."

New demand

Soon afterwards, state television showed ruling party leaders signing the pact at the palace as Saleh and the US ambassador stood behind them, but Saleh did not sign the document.

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Hakim al-Masmari, the editor of The Yemen Post, told Al Jazeera the move was an attempt by Saleh to avoid looking "like a president who was ousted from power".

"The opposition did not want to go to the palace because it knows that the revolution leaders in Sanaa will be very angry ... because it will destroy the mission of the revolution," he said.

"It will make Saleh look victorious, like a person who is leaving power with honour and dignity, rather than a person who has killed hundreds of Yemenis over the months of the Yemen revolution."

Yemen's opposition coalition signed the deal on Saturday, based on what it said were guarantees that the president would sign on Sunday.

Saleh had backed away from signing the Gulf deal at least twice before.

Officials trapped

Earlier, European, US and Arab ambassadors, who were pressing Saleh to sign the accord, were trapped for hours in an embassy surrounded by armed government supporters.

Eventually Yemeni army helicopters ferried the diplomats to the signing ceremony.

Yemen has been reeling from months of street protests that have seen tens of thousands of people massing in Sanaa, calling on Saleh, who has ruled Yemen for 32 years, to step down.

Taiz and the port city of Aden have also been scenes of mass protests.

Protesters say that the Gulf-brokered deal falls short of their demands for Saleh's immediate departure and the dismantling of his regime.

They have also rejected any immunity for Saleh and say that the opposition parties do not speak for their demands.

Source: Al Jazeera and agencies