Congolese Opposition Leader Tshisekedi is Dead.

Etienne Tshisekedi, Congo’s opposition icon who fought for democratic reforms for decades in the country has died At the age of 84.

His death comes at a politically fragile moment for Congo, where he was heavily involved in the recent deal to get President Joseph Kabila to agree to step down by the end of this year after months of deadly protests. The parties signed a deal that has yet to be implemented.

The stalemate already had worried observers, and Tshisekedi’s death likely will compound the difficulties.

Tshisekedi had been seeking medical treatment in Belgium, Congo’s former colonizer. He has long battled rumors of ill health because of complications from diabetes.

In 2010, he walked the 15 miles (25 kilometers) from the airport to his suburban home in Kinshasa upon his triumphant return from medical treatment abroad.

A statement released by the party spokesman Augustin Kabuya did not state a cause of death.

Radio France Internationale said he died from a pulmonary embolism. It was not immediately clear when his funeral would be held back home in Congo.

With his death, Tshisekedi did not live to see whether Kabila will make good on his promise to leave by the end of 2017.