The United States says authorities in the Democratic Republic of Congo should restore broadcasts by Radio France International. Those frequencies were blocked this week over the station's reporting on political opponents of President Joseph Kabila.

Congolese authorities say they switched off RFI's six FM frequencies while a new, state-run media regulatory authority considers the station's coverage of the long-time opposition leader Etienne Tshisekedi.

U.S. State Department spokeswoman Victoria Nuland says the move breaches freedoms of speech and should be reversed immediately.

"We are concerned about these reports of Radio France International having been shut down. We urge the relevant Congolese authorities to reinstate RFI's frequencies immediately. And we continue to advocate to all Congolese political leaders and their supporters to act responsibility and to renounce violence," said Nuland.

Kabila won re-election in a vote marred by violence and wide-spread irregularities, including the loss of ballots from more than 3,000 polling stations. Tshisekedi rejected the results and declared himself president with his own swearing-in ceremony and new year's address to the nation.

Congolese information minister Lambert Mende told the French news agency the Kabila government "did not at all appreciate" RFI coverage of what he called Tshisekedi's "anti-constitutional comedy."

Following the voting irregularities, State Department spokeswoman Nuland called for Congolese authorities to proceed with "maximum openness and transparency" in their review of the results.

Congo's supreme court rejected an opposition challenge and declared Kabila the winner.