The US is “deeply concerned” about allegations that Rwanda is backing M23 rebels in neighbouring Democratic Republic of Congo and that Congolese troops are working with a Rwandan rebel group, US Secretary of State John Kerry said yesterday.

Chairing a UN Security Council debate on Africa’s Great Lakes region, Kerry urged the African leaders who signed a UN-mediated peace deal in February aimed at ending two decades of conflict in eastern Congo to respect the country’s sovereignty.

UN experts reported to the UN Security Council’s Congo sanctions committee last month that M23 continues to recruit fighters in Rwanda with the aid of sympathetic Rwandan military officers, while elements of the Congolese military have cooperated with Rwandan Hutu rebel group FDLR.

Rwanda and Congo have both denied the allegations.

“The US is deeply concerned about recent reports of resumed external support to M23 as well as of collaboration with the FDLR,” Kerry told the Security Council.

“I want to be emphatic here today - all parties must immediately end their support for armed rebel groups,” he said. “All governments must hold human rights violators and abusers accountable. We must end the era of impunity.”

While Kerry did not name Rwanda, US State Department spokeswoman Jen Psaki on Tuesday specifically called on Rwanda to end support for M23 rebels, saying there was evidence Rwandan military officials were involved.

The US spotlight on Congo and the Great Lakes region while the US is president of the UN Security Council in July builds on President Barack Obama’s first extended visit to Africa a month ago and renewed focus on the continent.

“The suffering in the Great Lakes ... is a high level priority for President Obama and for me and it is one that we believe must be met by high level leadership,” Kerry said. The Obama administration last month appointed Russ Feingold, a former US senator, as the first US special representative to the Great Lakes region.

Millions of people have died from violence, disease and hunger since the 1990s as foreign-backed rebel groups have fought for control of eastern Congo’s rich deposits of gold, diamonds, copper, cobalt and uranium, destabilising the Great Lakes region at the heart of Africa.

Kerry welcomed the recent deployment of a new 3,000-member UN Intervention Brigade to fight and disarm rebels in the east. The brigade is part of a 17,000-strong UN peacekeeping force, which has been stretched thin by the M23 rebellion.