PARIS -- After games on three continents and a whirlwind of ceremonies and travel, Team USA has finally arrived in the Olympics' host city.

And coach Steve Kerr had a corresponding message: It's time to act like it.

After a sobering film session Thursday that showed clips of some lackadaisical play, Kerr put Team USA through its most aggressive practice since coming overseas, hoping to ignite more spirit ahead of its Olympic opener Sunday against Serbia.

"That's what today is about. It's the reminder. It's time. We're here," Kerr said. "So it's got to be 40 minutes of force and attention and focus, and we can't let teams outplay us effort- and energy-wise like we did the other night against Germany, like we did against South Sudan."

Kerr specifically felt the team played slowly and didn't take advantage of its depth in those two games. Germany especially was beating the U.S. to loose balls, and the extra possessions were a major factor. This after the U.S. won by just four points after surviving three last-second shots to beat South Sudan.

The Americans are significant favorites in Paris, as usual, but Kerr and the coaching staff are really emphasizing how fragile the nature of the Olympic tournament can be. The U.S. could likely afford a loss in the three-game pool play -- it had them in 2004 in Athens and in 2021 in Tokyo and advanced to the medal round both times -- but after that, it's single-elimination for the gold.

The way Team USA played in London was not the type of energy required for such a reality.

"It's literally six games and, watching the tape, we're jogging through some possessions," Kerr said. "We're not hitting bodies on boxouts. And so it's time. It's time to lock in on that."

The Americans began their preparation for Serbia by walking through some sets Wednesday. Serbia is a legit threat to win the gold with Nikola Jokic at center and NBA-quality guards.

In the exhibition games, there wasn't as much attention placed on opponent personnel as Team USA focused on its own operations. But that is at an end as well. Team USA deployed scouts around Europe to watch and evaluate pre-Olympic matches to help prepare game plans.

Kerr, a four-time champion as NBA coach and an assistant on the gold medal-winning team in Tokyo, and his staff are raising their games and expecting the players to follow.

"We have another level. I think we have another two levels that we can get to, but it's a collaboration always," Kerr said. "So we can show the strategic stuff on the tape walk-through. We can show them, 'Let's do this, let's do that. Let's learn personnel.' We got to know the shooters, know the non-shooters, all that stuff. So that's where we can help them. Where they can help themselves is just effort and energy play after play, after play. This is different."

Friday will be a special day as the players will visit the Olympic Village to spend time with their fellow American Olympians. Then they will ride on the Team USA boat for the opening ceremony down the River Seine through the heart of Paris in a truly unique and historic event.

Then it will be all basketball.

"You tend to just stay in the moment and realize this is a special time," Kevin Durant said Thursday. "It's just been cool being around all of these great players and seeing 'em in a different element outside of just being competitors. As teammates, you always got that competitive fire."

Said Kerr: "This should be one of the great experiences of our lives. But the best way to make it an incredible experience is to win a gold medal."