Felix Tshisekedi of Congo had long said his country would not negotiate with the Rwanda-backed militia, making the joint agreement a rare bright spot in the conflict.

US Secretary of State Marco Rubio on Friday will host the signing of an agreement between Rwanda and the Democratic Republic of Congo following a truce pledge, officials said.The State Department on its public schedule said that Rubio would sign a "declaration of principles" with DRC Foreign Minister Therese Kayikwamba Wagner and Rwandan Foreign Minister Olivier Nduhungirehe.

The long-running conflict worsened in January after M23 launched a major attack that killed more than 700 people.