By Robert Birsel
BENGHAZI, Libya (Reuters) - Libyan leader Muammar Gaddafi's days are numbered as rebel forces make steady gains on the battlefield, and opposition leaders must work together to prepare for power, a senior U.S. official said Saturday.
"It is clear that the situation is moving against Gaddafi," U.S. assistant Secretary of State Jeffrey Feltman told a news conference after meeting Libyan rebel leaders at their headquarters in Libya's eastern city of Benghazi.
"The opposition continues to make substantial gains on the ground while his forces grow weaker," Feltman said. "It is time for Gaddafi to go and we firmly believe that his days are numbered."
The United States has recognized the rebels' National Transitional Council (NTC) as Libya's legitimate authority. Feltman called on its leaders to uphold human rights and ensure an inclusive and representative government after Gaddafi goes.
They should work together now and plan to establish the rule of law, set up transparent and accountable institutions and provide safety and services.
Washington has helped the rebels by backing a NATO bombing campaign against Gaddafi's troops, although U.S. forces have played a backseat role since the initial days of the bombing, leaving French and British warplanes in the lead.
Feltman said the United States supported efforts by a U.N. envoy to negotiate a solution, but Gaddafi had yet to agree to the demands of Washington and others that he leave power.
"So far, the essential element of negotiations, an agreement by Gaddafi that he is ready to step down, hasn't happened."
Rebel progress on the battlefield has accelerated over the past few weeks, especially in the west on the approaches to Tripoli. But the opposition has also been hampered by divisions, revealed starkly in late July when their military chief was assassinated in circumstances yet to be fully explained.
Abdel Fattah Younes, a former top Gaddafi security official, was killed on July 28 after he was taken into custody by his own side for questioning. The killing has raised fears of a weak NTC unable to halt a slide into bloodshed as rival factions, including Islamists, bid for power in a post-Gaddafi Libya.
The NTC responded to the killing by launching investigations and sacking the entire rebel cabinet. Feltman said that showed its leaders understood the need for accountability.
"What happened here was bad, but the NTC, it seems to us, is dealing with this transparently, it's dealing with it in a way that includes credible investigation, that includes attempts at reconciliation and includes some accountability," he said. "No one here has tried to sweep this under the rug."
(editing by Elizabeth Piper)