WASHINGTON — Secretary of State John Kerry on Tuesday selected a former Senate colleague, Russ Feingold, to serve as a special envoy to the Great Lakes region of Africa, promising to raise the profile of a region torn by conflict and yet largely overshadowed in American foreign policy by other global crises.

Mr. Feingold will oversee policy for a region that includes Uganda, Rwanda, Burundi and the eastern reaches of the Democratic Republic of Congo, where a rebel force known as the March 23 Movement continues to threaten a weak central government. “For the president and for me, this is a high-level priority,” Mr. Kerry said, “and it needs to be met with high-level leadership.”

Mr. Feingold, a liberal Democrat, represented Wisconsin in Congress for 28 years, first as a representative and then for three terms as senator before losing a re-election campaign in 2010 to Ron Johnson, a Republican. Although better known for campaign finance legislation that included his name, along with Senator John McCain’s, Mr. Feingold served as chairman of a Senate subcommittee on Africa and was, Mr. Kerry said, widely recognized as one of the Senate’s leading experts on the continent. He replaces R. Barrie Walkley, an ambassador and career Foreign Service officer who was appointed to the position in December 2011.

In March, the United Nations authorized a new “intervention brigade” of peacekeepers with an explicit mandate to help the Congolese government defeat armed rebel groups, the first such international deployment. Congo’s eastern provinces have been roiled by fighting ever since the genocide in Rwanda in 1994 resulted in the flight of thousands of Hutus to the region. Rwanda’s Tutsi-led government has sent troops across the border several times since then to attack Hutu militias. The creation of the brigade, headquartered in the provincial capital, Goma, followed an agreement signed by the United Nations and 11 neighboring nations to try to end the overlapping conflicts in the region.