Uganda said on Monday it would stop mediating in the conflict between the Democratic Republic of Congo and M23 rebels if the U.N. Security Council endorsed accusations that Uganda was supporting the rebels.

A report by a U.N. panel of experts leaked to Reuters last week accused Uganda and Rwanda of providing support to M23, whose insurgency has displaced half a million people in North Kivu province, which borders both countries.

The report, written for the U.N. Security Council's Congo sanctions committee, said Uganda had allowed M23's political branch to operate from Kampala in addition to providing M23 with troops, weapons, technical help, political advice and facilitation of external relations.

"We have contacted the U.N. via our diplomats in New York because we want to know whether what the media wrote about is true," junior foreign affairs minister Asuman Kiyingi told Reuters.

"If the U.N. confirms its experts wrote these outrageous falsehoods, then we'll withdraw from our mediation role in the conflict between Congo and the M23 rebels."

Kiyingi said the allegations were already undermining the perception of Uganda as a neutral mediator.

The Ugandan government has already denied it supports M23, calling the allegations "rubbish, rubbish, rubbish."

Congo has demanded sanctions on Ugandan and Rwandese officials funneling support to M23. The U.N. Security Council on Friday adopted a statement expressing an intention to impose sanctions on M23's leaders and those who violate a U.N. arms embargo on Congo.

Uganda has been spearheading faltering efforts by a regional body, the International Conference on the Great Lakes Region (ICGLR), to put together a 4,000-strong force to neutralize M23 and police the border between Congo and Rwanda.

U.N. peacekeeping chief Herve Ladsous told reporters at the United Nations in New York on Monday that no countries bordering the Democratic Republic of Congo would be contributing troops to such a force.

"There is a military assessment team that is meeting in Goma so we have to wait for their recommendations," Ladsous said. "It is still being worked upon but we expect some results in the next few days."

"Of course the devil is in the details and we would have to look very closely at the composition of that force, at its command and control mechanisms, how to coordinate with (U.N. peacekeepers) and agree on very specific objectives," he said.

Kiyingi said Uganda would stop its mediation role even if the United Nations did not endorse the accusations but still imposed sanctions on M23 leaders.

"We cannot try to bring two parties to the table to talk when one is under sanctions and the other is not," he said. Reuters