The United States on Wednesday welcomed a top Congolese court's certification of Felix Tshisekedi as the new president of the Democratic Republic of Congo (DRC).

The country's Constitutional Court on Sunday backed Tshisekedi's contested presidential election victory, but his main rival rejected the ruling, called for protests and declared himself leader.

"The United States welcomes the Congolese Constitutional Court’s certification of Felix Tshisekedi as the next President of the Democratic Republic of the Congo (DRC)," State Department spokesperson Robert Palladino said in a statement. "We are committed to working with the new DRC government."

Last month's election was meant to mark the first democratic transfer of power in the vast central African country, where conflicts have regularly destabilized the region.

But monitors pointed to major flaws in the voting. Unrest over the vote has already killed 34 people, wounded 59 and led to 241 "arbitrary arrests" for the week after the provisional results were announced on January 10, according to the UN human rights office.

"We encourage the government to include a broad representation of Congo's political stakeholders and to address reports of electoral irregularities," Palladino said.