The United Nations Security Council this week said it was concerned by "escalating violence" in the eastern Democratic Republic of Congo, in a statement condemning the offensive launched earlier this month by M23 rebels near the city of Goma.
Clashes have intensified recently between the M23 - among the strongest of dozens of armed groups roaming the country's troubled east -- and the Congolese army.
The DRC, the UN and Western countries say Rwanda is supporting the rebels in a bid to control vast mineral resources, an allegation Kigali denies.
Council members, who met Monday to discuss the issue, "reiterated their condemnation of all armed groups operating in the country. They expressed concern about the escalation of violence and a sustained tension in the region," according to a statement read by Guyana ambassador Carolyn Rodrigues-Birkett.
Council members also specifically "condemned the M23 offensive," launched February 7, Rodrigues-Birkett said.
"They reiterated their full support to the sovereignty, unity and territorial integrity of the DRC."
The M23 has seized vast swaths of North Kivu province since emerging from dormancy in late 2021, in an area destroyed by violence for decades following regional wars in the 1990s.
The most recent flare-up has pushed thousands of civilians to flee the town of Sake, on the route towards Goma, capital of North Kivu province.
According to a UN document seen by AFP earlier on Monday, the Rwandan army is using sophisticated weapons such as surface-to-air missiles to support M23.
A "suspected Rwandan Defence Force (RDF) mobile surface-to-air missile (SAM)" was fired at a UN observation drone last Wednesday without hitting it, the confidential report said.
UN forces have been in DRC for nearly 25 years, but stand accused of failing to protect civilians from armed groups.
The UN Security Council voted in December to accede to Kinshasa's demand for a pullout despite the volatile situation.
Meanwhile, close to 3,000 South African National Defence Force soldiers have been deployed to the eastern part of DRC to fight the rebels alongside allied forces, the government indicated.
The deployment affirms South Africa’s commitment to the Southern African Development Community (Sadc) mission.