Washington (CNN) -- The United States called the recent presidential elections in the Democratic Republic of Congo "seriously flawed" but said it was unclear whether the irregularities were enough to change the outcome of the election in the central African country.
"We encourage the relevant Congolese authorities to closely review these cited irregularities and proceed with maximum openness and transparency," State Department spokeswoman Victoria Nuland said in a written statement Wednesday.
The assessment was based on information gathered by staff members at the U.S. Embassy in Kinshasa, as well as views expressed by other diplomatic missions to U.S. officials and outside monitoring organizations like the Carter Center.
Based on such reports, "we believe that the management and technical execution of these elections was seriously flawed, lacked transparency and did not measure up to the democratic gains we have seen in recent African elections," Nuland said.
Incumbent President Joseph Kabila was declared the winner last week by the country's election commission. Kabila, who took power of the resource-rich country after his father's assassination in 2001, received 48.9% of the vote, the commission said.
Etienne Tshisekedi, the main challenger, had warned that the opposition would not accept the results of the election amid reports of ballot-stuffing and other fraudulent claims. Human Rights Watch reported that at least 18 people had been killed in election-related clashes after the vote.
In her statement, Nuland said the administration believed that a "rapid technical review" of the process by Congolese government authorities could be a mechanism to provide more credible results and see whether the irregularities were caused by outright fraud or poor organization on the part of election officials.
The Congolese government is responsible for providing security for its people and must hold to account anyone who uses violence to derail the democratic process, Nuland said.