The two teams square off Sunday in Los Angeles.
"We have championship aspirations, but at the end of the day, that's not what's here right now," James said. "What's right now is our next opponent, and that's Dallas. And they're very good. And we want to continue to get better and better and have a championship mindset every time we step on the floor.
"Playing at championship level, we have guys that have been there who know what it takes, so that helps for sure."
The Lakers tied a franchise record by improving to 17-2 through the season's first 19 games after they posted a 125-103 win over the Washington Wizards on Friday.
Anthony Davis scored 26 points, pulled down 13 rebounds and blocked three shots in 27 minutes for the Lakers, who matched the 1985-86 and 2008-09 Lakers' teams for best starts to a season. Los Angeles has won 10 in a row.
"Obviously, our goal is to add another banner here," Davis said. "It's something we feel like we can do, and if we do that, to be a part of that would be nothing but great."
James finished with 23 points and 11 assists in 25 minutes as six Lakers reached double figures. Neither James nor Davis played in the fourth quarter.
Dallas' Luka Doncic is coming off a standout outing in the Mavericks' 120-113 win at the Phoenix Suns on Friday. Doncic had 42 points, tying a career high, with 11 assists. Doncic connected on 12 of 24 shots from the floor and 15 of 18 free throws.
Doncic's big night occurred after he struggled with a 4-for-14 shooting performance in a 114-99 loss at home to the Los Angeles Clippers on Tuesday.
"Great players have a short memory for tough games and they move forward and they're always thinking ahead," Dallas coach Rick Carlisle said, per NBA.com. "They're always thinking about the next challenge, and he was spectacular tonight from start to finish."
Tim Hardaway Jr. contributed 26 points on 8-of-14 shooting from the floor, including 6 of 9 from 3-point range. Seth Curry scored eight of his 11 points in the fourth quarter.
"We played our best when we get a lot in the paint, so that was key for us," said Doncic, who is averaging 30.8 points, which was third best in the NBA entering Saturday's games.
Doncic is almost averaging a triple-double, putting up 9.9 rebounds and 9.6 assists per contest.
The Mavericks prevailed despite Kristaps Porzingis, who averages 17.3 points, being limited to two points. Porzingis missed all eight of his field goals, including six from behind the arc. However, the 7-foot-3 center grabbed 13 rebounds and recorded three blocks.
Lakers forward Kyle Kuzma sustained a mild ankle sprain near the end of the third quarter against Washington. He is considered day-to-day.
Los Angeles guard Avery Bradley, who has been out with a hairline fracture in his right leg, was scheduled to be re-evaluated Saturday to determine his availability.
The Lakers beat the Mavericks 119-110 in overtime in Dallas on Nov. 1. James (39 points, 16 assists, 12 rebounds) and Doncic (31 points, 15 assists, 13 rebounds) each recorded triple-doubles.
--Field Level Media