* Africa's Great Lakes region a U.S. priority, says Kerry
* U.S. says evidence Rwanda supporting M23 rebels in Congo
* Rwanda and Congo deny experts' claims of rebel support
By Michelle Nichols
UNITED NATIONS, July 25 (Reuters) - The United States 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, Secretary of State John Kerry said on Thursday.
Kerry, chairing a U.N. Security Council debate on Africa's Great Lakes region, urged the African leaders who signed a U.N.-mediated peace deal in February aimed at ending two decades of conflict in eastern Congo to respect the country's sovereignty.
U.N. experts reported to the U.N. 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 United States 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, U.S. State Department spokeswoman Jen Psaki on Tuesday specifically called on Rwandato end support for M23 rebels, saying there was evidence Rwandan military officials were involved.
The U.S. spotlight on Congo and the Great Lakes region while the United States is president of the U.N. 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 U.S. senator, as the first U.S. 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, destabilizing the Great Lakes region at the heart of Africa.
Kerry welcomed the recent deployment of a new 3,000-memberU.N. Intervention Brigade to fight and disarm rebels in the east. The brigade is part of a 17,000-strong U.N. peacekeeping force, which has been stretched thin by the M23 rebellion.
M23 is a Tutsi-dominated rebellion of former Congolese soldiers that has demanded political concessions from PresidentJoseph Kabila's government. The group began taking over parts of eastern Congo early last year.
Several Western countries, including the United States, Britain and Sweden, froze aid last year over accusations that Rwanda is waging proxy war across the border.
The 15-member U.N. Security Council, which currently includes Rwanda, on Thursday agreed on a statement that "calls on all countries of the region neither to tolerate nor provide assistance or support of any kind to armed groups." (Reporting by Michelle Nichols; Editing by Vicki Allen)