The U.S. and Saudi Arabia pressured Yemen's president to stay in Saudi Arabia after he was released from a lengthy hospital stay to treat wounds suffered in an assassination attempt, according to Yemeni officials.

The officials, speaking to The Associated Press on condition of anonymity because of the sensitivity of the subject, said Monday the U.S. and Saudi warned Ali Abdullah Saleh that his return to Yemen would likely spark a civil war.

In Washington, U.S. State Department spokesman Mark Toner said it was up to Saleh to decide whether to stay on in Saudi Arabia or return home and that a transition of power should begin immediately regardless of what Saleh decides to do.

"All we can do is continue to press our belief that this transition needs to happen immediately and cannot wait until a decision is made about his (Saleh's) future," he said. "So, what we're working on, through our embassy and our ambassador, is trying to move the process forward now, rather than wait."

The Yemeni officials said that even though Saleh has spent the last two months in a Saudi hospital, he continues to run the country with the help of his family and is in daily contact with tribal chiefs and army commanders.

"The president reluctantly caved in to American and Saudi pressure to stay on in Saudi Arabia," said one official who is close to Saleh. "He will continue to listen to them until he makes a full recovery from his wounds and then decide what to do."

In Washington, a U.S. official cast doubt on the idea of American pressure on Saleh to stay on in Riyadh after his release from the hospital on Sunday.

"It is more likely that any persuasion used successfully with Saleh came from the Saudis," said the official, who also spoke on condition of anonymity because of the sensitivity of the subject.

Saudi Arabia is among Washington's staunchest Arab allies and has over the past six decades cooperated with the United States on many aspects of Mideast policy.

Saleh has clung to power in the face of six months of massive street protests across his impoverished nation in the southern corner of the Arabian Peninsula, much like the uprisings sweeping across other parts of the Arab world.

The protests often turned violent, with Saleh's security forces using deadly forces against the protesters. Army forces loyal to Saleh and led by his son Ahmed, the president's one-time heir apparent, have also clashed with opposition tribesmen in Sanaa, using mortars, artillery and rockets and damaging parts of the Yemeni capital.

Yemen overlooks strategic shipping routes in the Red and Arabian seas and is not far from the vast oil fields of Saudi Arabia. It has one of the most active Al-Qaeda branches in the world and the United States sees the growing unrest there as a threat to its effort to fight the terror network. Both Saudi Arabia and the United States have been hit by attacks or foiled attacks on their territory that were plotted by Al-Qaeda in Yemen.

Saleh was rushed to Saudi Arabia in June for emergency medical treatment at the height of the uprising. Since he left, the country has been in a kind of limbo, with both the protesters demands and the question of who will succeed Saleh unresolved.

If he stays in Saudi without relinquishing power, it will sink Yemen deeper into political uncertainty and perpetuate a security vacuum which al-Qaeda-linked militants have already taken advantage of, capturing and holding towns in the nearly lawless south of the country, even though many have accused Saleh of creating a security vacuum on purpose to frighten Yemenis of the uprising.

Saleh's deputy, Vice President Abed Rabo Mansour Hadi, is nominally in charge in Saleh's absence. But the real power on the ground appears to be Saleh's son Ahmed, who controls the country's best trained military forces and the powerful Hashid tribal confederation, which opposes the regime.

The government officials said Saleh was in daily contact with Ahmed, his son, tribal leaders loyal to him and top military officers. Ahmed Saleh himself was assuming some of his father's duties, receiving tribal envoys at his Sanaa office and spending some of his time at the presidential palace. Hadi,
meanwhile, continues to work from home or the defense ministry.

"The vice president really does very little and has limited authority," said one of the Yemeni government officials. "It is the president's son Ahmed and his nephews who run the country."

A Western diplomat who recently met with Saleh's son Ahmed said a long line of tribesmen and others waited outside his office to see him and that he was lavishing cash gifts on some of them.

Patronizing tribesmen has been a hallmark of Saleh's 33 years in power, a practice that secured him support he often used against his critics.

The diplomat spoke on condition of anonymity, also because of the sensitivity of the subject.

Saleh was severely burned over large parts of his body in a June 3 attack on his compound in Sanaa, Yemen's capital. He also had chunks of splintered wood embedded in his chest. After his release from two months in the hospital on Sunday, he was moved to a residence in Riyadh to continue recuperating. There has been no indication if, or when, he might return home.

Saleh has on three occasions announced he was ready to accept proposals by Saudi Arabia and its Gulf Arab allies to defuse the political crisis, but he has backed off at the last minute.

The plan provided for Saleh to hand over power to his deputy in exchange for immunity from prosecution. The country's traditional opposition parties, a collection of Islamist, leftists and tribal-based groups, have accepted the plan but leaders of the street protests have rejected it, insisting that Saleh must step down unconditionally and be prosecuted.