A top American official says the country will respond to what it calls a clear violation of a U.S.-brokered agreement, as rebels seize a major city and risk spreading the conflict.
Top American diplomat Marco Rubio said Saturday that Rwanda has clearly broken a peace deal signed last week with the Democratic Republic of Congo. He promised the United States would take action in response. This came after Rwanda-backed M23 rebels captured a key border city. The advance has greatly increased fears the conflict could grow into a wider regional war.
Secretary of State Rubio made the statement on social media. He said Rwanda's actions in eastern Congo were a clear violation of the Washington Accords. That deal was signed by U.S. President Donald Trump on December 4. Rubio wrote that the U.S. would act to ensure promises made to the president are kept. He did not give details on what that action would be.
The main trigger for this accusation was the fall of the city of Uvira. The M23 rebel group seized it this week. Uvira is on the northern tip of Lake Tanganyika. It lies directly across from Burundi's largest city, Bujumbura. The city's capture cuts off a major supply route for Burundian troops in Congo. It is also the Congolese government's last major foothold in South Kivu province.
The day before Rubio's statement, the U.S. ambassador to the United Nations spoke forcefully. Ambassador Mike Waltz told the U.N. Security Council that Rwanda is leading the region toward more instability and war. He said the U.S. would use the tools at its disposal to hold spoilers of peace to account.
Waltz provided specific allegations of Rwandan involvement. He said the Rwandan defense forces have given material, logistics, and training support to the M23. He also said between 5,000 and 7,000 Rwandan troops were fighting alongside the rebels in Congo as of early December. This support is said to include advanced firepower like surface-to-air missiles, drones, and artillery.
The military advance has caused severe human suffering. Regional officials report more than 400 civilians have been killed since the offensive escalated. About 200,000 people have been displaced from their homes. Many have fled across the border into Burundi.
This new fighting worsens one of the world's largest humanitarian crises. The overall conflict in eastern Congo has already displaced more than 7 million people. Earlier this month, U.N. experts said Rwanda's army and the M23 carried out summary executions. They also forced mass displacements of people in the region.
The capture of Uvira has sharply raised tensions with neighboring Burundi. The city is just 27 kilometers from the Burundian capital. Burundi has been a major ally of the Congolese government. It has thousands of troops in eastern Congo.
Burundi's ambassador to the U.N., Zephyrin Maniratanga, issued a strong warning to the Security Council. He said "restraint has its limits." He added that continued attacks would make it extremely difficult to avoid a direct escalation between Burundi and Rwanda. Burundi has now closed its border with Congo, though it is still allowing some fleeing civilians to cross.
Rwanda has firmly denied the American accusations. Its U.N. ambassador, Martin Ngoga, said Rwanda is not waging war against Burundi and has no intention of doing so. Instead, he accused Congolese and Burundian forces of violating the ceasefire.
Rwanda says it is fully committed to implementing its part of the Washington peace deal. The country's government argues its security is threatened by Congolese-based Hutu militias. These groups include the Democratic Forces for the Liberation of Rwanda (FDLR). Rwanda says the Congolese army protects these militias.
The crisis is a major setback for U.S. diplomatic efforts. President Trump had touted the Congo conflict as one of several wars he helped end since returning to office. He called the December 4 signing a "historic" and "great day for Africa".
The peace deal required Rwanda to stop supporting armed groups like the M23. It also called for economic cooperation between the two nations. This was seen as a way for American companies to get better access to the region's critical minerals. The renewed fighting puts all these plans on hold.
The political crisis is affecting Rwanda's economy. The value of the Rwandan franc has fallen sharply. It lost nearly 10% of its value against the U.S. dollar in the last financial year. Analysts link this to a drop in foreign aid, especially from the U.S.. The aid cuts are tied to allegations over Rwanda's role in the Congo conflict.
In March 2025, the European Union imposed sanctions on Rwandan army commanders and the head of its mining agency. The EU accused them of involvement in illegal resource extraction in eastern Congo. These economic pressures add another layer of difficulty for Rwanda's government.
Experts are unsure why the M23 launched this offensive now. One theory is the rebels wanted more leverage in separate peace talks hosted by Qatar. Another view is Rwanda's government does not trust Congolese President Felix Tshisekedi to keep his word.
The future of the U.S.-brokered peace process is now in doubt. Professor Jason Stearns, a regional expert, told the BBC the process is on a "troubled path, perhaps it is stuck". He noted a key part of the deal required Congo's army to disarm the FDLR militia. That operation is unlikely to happen now.
The U.S. has pledged to respond but has not said how. Congo has asked the U.N. Security Council to impose sanctions. It also wants a ban on Rwandan mineral exports. For now, the fighting continues. Millions of civilians remain caught in a conflict that risks drawing in more countries.