Head coach Steve Kerr said the United States would have to sharpen up after they suffered their first loss of the Basketball World Cup on Sunday, going down to Lithuania but still advancing to the quarter-finals.

The US launched a furious second-half comeback after falling into a big hole before the interval, but it was not enough to stop Lithuania from claiming a 110-104 win.

Kerr said he "loved the way our guys fought back" but warned they would have to start faster when they face Italy in the quarter-finals on Tuesday in Manila.

"We needed to feel this, we needed to respond, and next game we have to start the way we did in the second half," he said.

"We can't ease into the game at all. I'm hoping that this is a lesson and we get better from this."

Kerr said Lithuania "came out of the gates on fire", nailing their first nine three-point attempts to rack up a 17-point lead at half-time.

The US fought back, outscoring Lithuania 28-17 in the third quarter, but the Europeans kept their noses in front to preserve their unbeaten record at the tournament.

Kerr said Lithuania, who will face Serbia in the quarter-finals, were "brilliant" and "were carving us up" in the first half.

"We're fortunate that the loss doesn't hurt us in terms of our goal, which is to win the gold medal," he said.

"But it's a great game for us to experience because this is FIBA.

"There's some great teams that have continuity, that understand what they're doing, that execute."

Anthony Edwards finished as the game's top scorer with 35 points, while Vaidas Kariniauskas led Lithuania with 15 points.