Paris, France - Bam Adebayo led the US with 18 points in a 103-86 win over South Sudan on Wednesday as the reigning champions sailed into the quarter-finals of the Olympic men's basketball tournament.

Team USA have never lost to an African side at the Olympics but they had a scare when they played South Sudan in a warm-up game in London on July 20.

However, there was never any threat of an upset in Lille as LeBron James got the US, seeking a fifth successive gold medal, off to a fast start in the first quarter and never looked back.

Jayson Tatum began the game for the US after coach Steve Kerr kept the Boston Celtics star on the bench for the entirety of Sunday's opening win over Serbia.

Instead, it was the turn of Joel Embiid to sit out the evening as Adebayo had the hot hand, the Miami Heat center making his first six shots and eight of 10 in total.

Kevin Durant chipped in with 14 points, producing another solid shooting display after his return from injury against Serbia, while James finished with 12 points.

"You've got guys from all ages in the league that [have] accomplished so much, but they're all unselfish players who want the best for the team," said Durant.

"I think we've got to continue to prove ourselves because other teams I've been on we won the gold, but as far as talent and what we look like on paper, it's probably the best team I've played on."

Anthony Edwards, Derrick White, and Devin Booker all reached double digits as well, but it was a tough night for Stephen Curry, who finished with just three points.

The US led 55-36 at half-time, and while South Sudan fought bravely to stay in the contest, the Olympic newcomers could never get back to within fewer than 10 points.

"I think a team like this we need to put our foot on the gas for 40 minutes straight," added Durant, a three-time gold medallist.

Nuni Omot scored a game-high 24 points for South Sudan, with Carlik Jones adding 18 for a team coached by former NBA player Royal Ivey.

With two wins from two in Group C, the US are now guaranteed to advance to the last eight. Canada, Germany, and hosts France had already secured their passage to the quarter-finals.

South Sudan, who began their Olympic debut with a win over Puerto Rico, remain well positioned to make the knockout phase.

Earlier on Wednesday, Serbia bounced back from their opening loss to the US with an emphatic 107-66 win over Puerto Rico.

Three-time NBA MVP Nikola Jokic came up just short of a triple-double as he registered 14 points, 15 rebounds and nine assists.