Yemeni President Ali Abdullah Saleh is trying to salvage his 32-year rule by negotiating an exit with the towering array of opponents including key military commanders and tribal leaders demanding that he immediately step down.

Back-channel negotiations between the controversial U.S. ally and Maj. Gen. Ali Mohsen al-Ahmar—a top commander who withdrew his loyalty from the president on Monday—haven't yet yielded a clear transition of power, but the political process so far has succeeded in keeping the power struggle from devolving into military conflict or civil war.

The prognoses of the talks remain unclear, and the threat of military conflict remains a possibility, according to officials in San'a. Saudi Arabia and Yemeni tribal leaders are involved in the negotiations, according to people familiar with the situation, but President Saleh appears to be staking out untenable terms.

His spokesman announced early Tuesday that the leader would agree to step down by the end of the year in favor of a military council taking over, The Wall Street Journal reported. An umbrella group of opposition political parties rejected a similar proposal when the president offered it last month in what appeared to be a bid to end the unceasing street protests against his continued rule.

However, The Associated Press quoted a spokesman for President Ali Abdullah Saleh as saying that the Yemeni leader vowed never to hand over power to the military.

At the same time it wrote that Saleh is willing to step down by the end of the year as part of a "constitutional" transfer of power.