A peace deal set to be signed on Monday between the Democratic Republic of Congo and defeated M23 rebels is "a very important step for peace".

A peace deal set to be signed on Monday between the Democratic Republic of Congo and defeated M23 rebels is "a very important step for peace", the UN's special envoy to the war-torn Great Lakes region told AFP Sunday.

"It's a very important step for peace in the Great Lakes because it enables us now to move forward," Mary Robinson said, vowing that the national army and a special UN intervention brigade would press on with efforts to defeat other rebel groups.