(Adds Bashir, Deby, Gaddafi quotes)
By Salah Sarrar
TRIPOLI, Feb 21 The leaders of Sudan and Chad said they agreed on Wednesday to redouble efforts to end violence spilling over their border from Darfur, scene of one of the world's worst humanitarian crises.
The accord was the only progress reported by officials at the end of a mini-summit of regional leaders that had also sought to widen rebel participation in a shaky peace for Darfur, where an estimated 200,000 people have been killed since 2003.
Violence in Darfur has expanded into Chad, which accuses Sudan of supporting rebels launching cross-border attacks that have exacerbated ethnic tensions and triggered a flood of refugees.
Libyan leader Muammar Gaddafi has pressed Chad and Sudan to settle their differences as part of efforts to bring peace to Darfur, where 2.5 million people have been driven from their homes since 2003.
The summit's other goal was to entice the National Redemption Front rebel coalition to meet Sudan's government to discuss joining a 2006 peace deal between Khartoum and a faction of the former rebel Sudan Liberation Movement.
There was no word on whether such a meeting took place.
Sudanese President Omar Hassan al-Bashir had said on arrival he would meet the rebels. But officials briefing reporters after the summit spoke only of the Sudan-Chad agreement, their third such accord in 12 months.
"We are opening a new page in Chad-Sudan relations with political will on both sides," Bashir said after the meeting of the leaders of Sudan, Chad, Libya and Eritrea. "We are approaching the realisation of peace in the Darfur region."
Majzoub Al-Khalifa, an adviser to Bashir, said Bashir and Deby had agreed to boost implementation of an accord struck in February 2006 requiring they stop insurgents setting up bases on their territories and end propaganda against one another.
He said "mechanisms of observation" would be set up to monitor any attempt to smuggle weapons across the frontier.
Chad President Idriss Deby said: "We regret all the violations we have witnessed and we are hoping to open a true and clean page. I hope the brothers in Darfur will reach a peaceful solution to the dangerous humanitarian situation."
In November 2006 Sudan and Chad pledged to redouble efforts to repair their frayed ties.
But relations have remained tense. Sudan's government denies accusations by Chad that it sends Janjaweed militia across the frontier and arms and directs rebels trying to overthrow Deby.
Gaddafi said he was encouraged by the Sudan and Chad accord.
"The brothers have now met around a table in a tent. This is great," he said. "I call on brothers in Darfur to give up their weapons, because carrying weapons in Sudan and Chad and between them is not acceptable."
The spiral of violence in Darfur has been slowed only by a huge humanitarian operation, which aid workers warn is increasingly under threat.
Washington calls the violence genocide, a term European governments are reluctant to use and which Khartoum rejects.
Bashir has resisted pressure to authorise deployment of thousands of U.N. peacekeepers to support a 7,000-strong African Union mission in Darfur.
Divisions among Darfur's rebel factions have been a factor in delaying an effective peace deal with Khartoum. One of the main factions complained on Wednesday it had not been invited to the talks in Libya and dismissed them as a "charade".