By Mark Doyle
BBC world affairs correspondent in Kigali
The UN Security Council has received a scathing response from Rwanda about UN plans for voluntarily disarming Rwandan rebels with bases in DR Congo.
A mutinational UN force is deployed in eastern DR Congo
The Security Council is on a tour of Central Africa to try to end a decade of genocide and armed conflict that has killed at least 4.5 million people.
At a meeting with the visiting ambassadors, Rwandan President Paul Kagame criticised UN tactics.
Mr Kagame said trying to disarm the rebels voluntarily would not work.
The UN ambassadors are now in Kinshasa for talks with President Joseph Kabila and other senior Congolese officials.
The French Ambassador, Jean Marc de la Sabliere, told the BBC the Security Council would urge the Congolese authorities to speed up their efforts in adopting a new constitution and making the necessary preparations for the general election due next year.
The issue of the Rwandan rebels that operate out of DR Congo and the tough line taken against them by the current Rwandan government is one of the most serious threats to stability in Central Africa.
DR Congo and Rwanda have gone to war over cross-border rebel groups several times.
The UN peacekeeping force in DR Congo has started military patrols in the area where the Rwandan rebels are based to encourage them to disarm.
But Mr Kagame, who accuses the rebels of being among those who committed the genocide of ethnic Tutsis and government opponents in 1994, told the BBC that voluntary disarmament would not succeed.
Inside the closed-door session with the Security Council, he said, according to diplomats, "If you want peace, you have to make war".
This was a clear snub to the UN peacekeeping force in DR Congo, which is accused by Rwanda of being ineffective against the rebels.
The Rwandan president's position presents a clear danger.
The leader of one of the most powerful armies in the region is strongly implying that if the UN does not achieve the disarmament of the rebels, he will - maybe by force.
Mr Kagame says he is trying to prevent a new genocide. That may be true, but his tough position also throws into question UN plans for peace in the central African region.