Congolese opposition leader Etienne Tshisekedi has died while in Brussels for a medical checkup; he was 84.
Tshisekedi's death was confirmed Wednesday by his political party, the Union for Democracy and Social Progress. He formed the party in 1982 to oppose the leadership of longtime dictator Mobutu Sese Seko, in the nation then known as Zaire.
The opposition leader, who served several brief stints as prime minister for Mobutu, had lived outside the Democratic Republic of Congo for several years before returning to the country in July, when he spoke at a rally opposing President Joseph Kabila's continued rule.
Tshisekedi's death comes at a tough time for Congo, where the opposition has been pushing for months to get Kabila to step down.
The president's term expired on December 19, but he has stayed in office in the absence of new elections. The government and opposition signed a political agreement that calls for elections by the end of this year, with Kabila remaining in charge of an interim government.
Tshisekedi was one of Kabila's most outspoken critics, and a popular and influential public figure. Last year, he called Kabila a "traitor" for refusing to step down.
Tshisekedi’s former chief of staff, Albert Moleka, told VOA that Tshisekedi's death presents a challenge to the Congolese people about whether they can show the world they have shared values and priorities.
Under the transition deal, Tshisekedi was set to take the top position in a transitional council for the interim government. The political agreement calls for the main opposition coalition, the Rassemblement, to choose a prime minister.