The United States on Friday urged DR Congo political leaders to sort out differences peacefully after President Joseph Kabila's rival rejected election results that gave a victory to the incumbent.
"We continue to call on all Congolese political leaders and their supporters to act responsibly, to renounce violence, to resolve any disagreements they might have through peaceful dialogue and existing legal remedies," State Department spokeswoman Victoria Nuland told reporters.
"The government of the DRC remains responsible for providing security for the people of the Congo, and any person who uses or incites violence to derail the democratic process should be held accountable," she said.
She also called on electoral authorities to ensure the credibility of the results by exercising "maximum openness and transparency."
Delayed results from the vast African country's second democratic election gave 49 percent of the vote to Kabila, who has been in power since 2001.
His rival Etienne Tshisekedi rejected the result and declared himself president, after which protesters set tires on fire and threw stones at armed police who fired tear gas to disperse them.
The United States has already voiced concern about the potential for violence in the Democratic Republic of Congo and prohibited diplomats from leaving the business district of the capital Kinshasa.