SAN'A, Yemen - Yemen's embattled president snubbed a U.S.-backed proposal by Gulf Arab nations that would end his rule and instead called Friday for new elections - a move unlikely to end the months of street protests demanding his ouster.

The announcement by Ali Abdullah Saleh dashed hopes for an end to the crisis in the Arab world's poorest country, home to one of al-Qaeda's most dangerous branches.

"This could go on for some time," said Christopher Boucek, a Yemen expert with the Carnegie Endowment for Peace. "He has been in power for 32 years, and this is not just luck. He has managed to figure out how to negotiate, balance, and manage different interests."

Saleh's announcement Friday to a crowd of cheering supporters in the capital, San'a, followed the apparent collapse of weeks of efforts by the six-nation Gulf Cooperation Council to mediate an end to the crisis.

The regional alliance tried to broker an agreement for Saleh to leave power in exchange for immunity from prosecution.

Saleh, who has all along refused before to sign such a deal, again declined to put his signature to the document Wednesday, prompting the GCC's head to leave Yemen. The next day, a spokesman said Saleh had changed his mind and would sign Sunday.

Saleh did not mention the agreement while speaking to tens of thousands of supporters near his presidential palace, nor did he say when the elections would take place.

"We call for early presidential elections to stop the bloodshed and to preserve traditions in a democratic and smooth manner," Saleh said.

In a nearby square, hundreds of thousands of his opponents called for his ouster.

The opposition rejected early elections, saying nothing short of Saleh's immediate departure would do.

"What the president said is a way to maneuver and flee from the crisis," opposition spokesman Mohammed al-Sabri said. "We insist that he sign the gulf proposal."

Behind the scenes, Saleh could be trying to negotiate a political future for himself and his party if he does sign the agreement. A ruling-party official said Saleh held meetings Friday with various government leaders to tell them he planned to sign the agreement Sunday.

More than three months of mass protests have nearly collapsed Yemen's shaky economy. Saleh has alternated between concessions and crackdowns. Nearly 150 protesters have been killed.

The United States, which considered Saleh an ally in fighting al-Qaeda, has backed away from him. President Obama said Thursday that "Saleh needs to follow through on his commitment to transfer power."