(CNN) -- Congo's highest court has upheld Joseph Kabila's win in last month's presidential election, striking down a lawsuit on Thursday that challenged the validity of the results.
Kabila is "happy with the decision and is happy to be moving forward with his government" in the Democratic Republic of the Congo, spokesman Mende Omalanga said.
The incumbent had faced 10 other candidates in the country's second democratic election.
This week, the U.S. called the elections "seriously flawed" but added that it was unclear whether the irregularities were enough to change the election outcome in the central African country.
Kabila was declared the winner last week by the country's election commission.
He 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.