Kenya will command the joint regional force, which will also include soldiers from Burundi, Uganda and South Sudan.
Kenya's President William Ruto has announced the deployment of troops to the eastern Democratic Republic of Congo in a joint regional operation against a rebel offensive.
Speaking at a ceremony in Nairobi on Wednesday, Ruto said the troops were "on a mission to protect humanity".
"As neighbours, the destiny of DRC is intertwined with ours," he added.
Armed groups in eastern DRC have stepped up attacks, reviving ancient animosities and unleashing a surge in tension with neighbouring Rwanda.
Leaders of the East African Community (EAC) agreed in April to establish a joint force to help restore security in the region.
Kenya will command the force, which will also include soldiers from Burundi, Uganda and South Sudan.
A Rwandan contingent will be deployed along the border after Kinshasa objected to Kigali's participation in any operations within the DRC.
The DRC accuses Rwanda of backing the militia, claims denied by Kigali.
The M23 rebels, a mostly Congolese group, resumed fighting in late 2021 after lying dormant for years, accusing the DRC government of failing to honour an agreement to integrate its fighters into the army.
The M23's resurgence has had resounding repercussions for relations in central Africa.
READ MORE: DRC expels Rwanda envoy over 'support' for M23 rebels
The UN chief @antonioguterres has called for immediate de-escalation in fighting between DR #Congo forces and #M23 rebels calling for all armed groups to down their weapons and disarm unconditionally @MONUSCOhttps://t.co/GaGPJ8tDIe— UN News (@UN_News_Centre) October 31, 2022
UN vehicles set on fire
Meanwhile, angry crowds set fire to United Nations vehicles in DRC's city of Goma as frustrations mount over the advance of M23 rebels and the deteriorating security situation in the country's east.
The violence late Tuesday came amid false rumours that the UN had transported rebels, adding to the dissatisfaction many people in eastern DRC have with the efforts of a peacekeeping mission known as MONUSCO.
“Because of these rebels, we have fled our homes in Rugari, Kibumba," protester Kasereka Munyafura said, standing next to the truck on fire. "That is why we are angry, and we have just burnt the vehicles of MONUSCO because it makes us suffer.”
Earlier on Tuesday, the UN peacekeeping mission in DRC announced a "strategic and tactical withdrawal" from embattled Rumangabo.
The M23 rebels have been trying to advance on the town, which houses a military base.
The mission tweeted that the decision was made "in consultation with our partners, to better prepare the next steps together."
READ MORE: Thousands of Congolese refugees fleeing fighting cross into Uganda