Bujumbura - UN Security Council ambassadors met for two hours with Burundian President Pierre Nkurunziza on Friday, but said they had made little headway in efforts to bring peace to the troubled central African nation.
The ambassadors met the president at his residence outside the capital during their second trip to the country in less than a year, appealing for him to take urgent action to stop the violence sparked by his re-election.
Council envoys have pushed for the government to hold talks with the opposition and agree to the presence of international troops - such as a proposed 5 000-strong African Union force - to restore stability.
But United States Ambassador Samantha Power said after the talks the envoys "didn't achieve as much, frankly, as I think we would have liked".
"There is a 'cri de coeur' from many, many people in Burundi for outside help and for urgent, urgent mediation to get a solution," Power added.
Burundi has been gripped by violence since April, when Nkurunziza announced his intention to run for a controversial third term, which he went on to win in July elections.
More than 400 people have died since then and at least 230 000 have fled the country, but Burundi's government insists there is no need for foreign troops and has branded AU peacekeepers an "invasion force".
Nkurunziza took a hard line during the meeting at his hilltop residence in Gitega, some two hours outside of Bujumbura, where he rejected calls for inclusive dialogue, renewed mediation efforts and an international intervention force.
He once again accused neighbouring Rwanda of backing armed opposition groups, and denied international warnings that the violence could turn into ethnic killings.
Relations between Rwanda and neighbouring Burundi are tense, with Bujumbura accusing Kigali of backing armed rebels and political opponents of Nkurunziza. Rwanda has denied all the claims.
"I can guarantee that there will not be a genocide in Burundi," Nkurunziza said, adding that Burundi is "99 percent secure".
Nkurunziza's refusal to compromise has raised the prospect of tougher measures ahead to stop almost nightly outbreaks of violence.
Clashes in Bujumbura on Thursday evening left three people dead, police said, including one youth who was shot dead by police after a grenade went off. Explosions and gunfire were heard in several places across the capital.