"I ... swear solemnly before God and the nation to abide by and defend the constitution and laws of the Republic, to preserve its independence and territorial integrity, to protect national unity," he said during a televised inauguration ceremony.
The 60-year-old won his first five-year term as president of the former Belgian colony in late 2018. His reelection was marred by accusations of fraud from opposition candidates, who called on their supporters to protest the inauguration. The court, however, ruled that there were no serious violations.
The Congolese election commission confirmed last month that Tshisekedi won the presidential race with 73% of the vote, versus 18% polled by his closest challenger, Moise Katumbi, a Congolese tycoon and one of the Central African nation's richest men.