A pro-UAE Yemeni official told AFP on Sunday that southern forces, including Emirati-backed separatists, would not agree to unite under the command of a Saudi-led coalition announced a day before.
Rashad al-Alimi, the head of Yemen's Presidential Council, had said Saturday that all military forces in southern Yemen would operate under the command of the Saudi-led coalition.
But Faraj al-Bahsani, a vice president of the separatist Southern Transitional Council (STC), said in an interview Sunday that it would be "difficult to unify forces" under the coalition banner.
"The southern forces, whether affiliated with the Southern Transitional Council (STC), the forces in Hadramawt, or any other force, will not accept this," he added.
Bahsani, who is also a member of the leadership council, is based in the United Arab Emirates, where he is receiving medical treatment.
He was previously governor of oil-rich Hadramout, one of two provinces bordering Saudi Arabia which the STC had captured before being forced out.
Alimi made Saturday's announcement days after Yemeni forces backed by Saudi Arabia had recaptured large swathes of territory from the UAE-backed STC, who had seized the two key provinces in December.