Rwanda and the Democratic Republic of Congo have signed an agreement to respect each other's sovereignty and come up with a draft peace deal by 2 May.

The deal was signed by the two countries' foreign ministers in Washington, with US Secretary of State Marco Rubio also present at Friday's ceremony.

Hundreds of thousands of civilians have been displaced in recent months as Rwanda-backed M23 rebels have seized swathes of mineral-rich territory in eastern DR Congo.

After losing territory, the government in Kinshasa turned to the US for help in exchange for access to the minerals.

Relations have been so poor between DR Congo and Rwanda that the meeting in Washington and a promise to resolve disputes through dialogue is a sign of progress.

The text of the agreement says both sides now expect significant investments facilitated by the US government and private sector.

Despite the talks, fighting reportedly continued on Friday in North Kivu province.

Earlier this week, DR Congo and the M23 group said they were committed to peace, expressing hopes that a permanent ceasefire could be reached.

Officials in eastern DR Congo say some 7,000 people have been killed there since January.

The decades-long conflict has intensified since the start of the year when M23 staged an unprecedented offensive, seizing Goma and Bukavu - eastern Congo's two largest cities - and sparking fears of a wider regional war.

DR Congo accuses Rwanda of arming the M23 and sending troops to support the rebels in the conflict.

Despite assertions from both the UN and US, Rwanda has denied supporting the M23.