"A political compromise has been reached on the implementation mechanism of the Gulf Cooperation Council (GCC) initiative between the ruling party and the opposition coalition," bin Omar told reporters after meeting with Yemeni Vice President Abd-Rabbu Mansour Hadi and the opposition leaders.

"We are now discussing the arrangements for signing theGCC initiative and its agreed implementation mechanism," he added, and congratulated the Yemeni people.

Bin Omar, who has visited Yemen to mediate the political crisis since July, finally declared his achievement during his sixth visit to follow up the implementation of the UN Resolution 2014 that called on President Ali Abdullah Saleh to sign the GCC initiative and end violence. The UN envoy was scheduled to hold a press release Tuesday morning, which was delayed to evening or Wednesday morning, according to a government official.

Meanwhile, an opposition official told Xinhua that "GCC chief Abdullatif al-Zayani is due to arrive in Sanaa soon to oversee the signing ceremony."

A senior government official ruled out that the signing ceremony will be held Tuesday, but rather within next few days.

On Monday, the Yemeni rival officials said they agreed to sign the UN-mediated GCC initiative on Tuesday to transfer power from President Saleh to his deputy Abd-Rabbu Mansour Hadi in return for immunity, and Saleh will retain his title as honorary president until a new leader for the country is elected.

They also said they agreed on the establishment of a mechanism to implement the GCC deal despite small differences.

The GCC initiative stipulates Saleh to hand over power to his deputy Abd-Rabbu Mansour Hadi and resign in 30 days in return for immunity from prosecution. Hadi would then form an opposition-led national government and arrange presidential elections in 60 days.

Saleh has backed out of signing the deal for three times in the last minutes.