A revised deal to end weeks of anti-government unrest and political crisis in Yemen appeared uncertain on Wednesday as both the president and opposition activists failed to sign an agreement.
News organizations earlier quoted an aide to President Ali Abdullah Saleh and an opposition official as saying the two sides would sign a plan brokered by the Gulf Cooperation Council later in the day.
But late Wednesday, the head of the Gulf bloc trying to mediate the accord left Yemen without an agreement. Opposition activists told foreign media that Mr. Saleh refused to sign an accord.
In Washington, the White House urged Mr. Saleh to implement the agreement "so that Yemen is able to move forward."
The group of six Gulf states earlier drafted a plan that offered President Saleh immunity from prosecution if he transferred power to a deputy within 30 days of signing. It also called for the establishment of a unity government that included the opposition.
However, the deal stalled in April when Mr. Saleh refused to sign it in his capacity as president, as required. He said he would only sign as head of the ruling General People's Congress party.
Reuters news quotes opposition official Yahya Abu Usbua as saying the updated agreement is a slight modification of the original plan and resulted from interventions by U.S. and European diplomats.
The Yemeni government has attempted to crack down on protests, but thousands of anti-government demonstrations have continued to take to the streets demanding President Saleh's immediate resignation.
Some information for this report was provided by AP, AFP and Reuters.