After Saturday's 2-0 loss at Old Trafford, Guardiola conceded that the better team won, and two days later he was very much of the same opinion when he spoke in Norway ahead of Tuesday's game against Bodo/Glimt.
"We're immediately thinking about this different competition, the chance we have to finish in the top eight," Guardiola told reporters.
"I think we didn't talk one word about United. I didn't review the game but I know right now, and even while watching the game at United, they were better. When a team is better you just have to congratulate them, improve, and move on."
City are fourth in the Champions League standings on 13 points, and a win at Bodo/Glimt in the penultimate league phase match would put them in the driving seat to qualify automatically for the last 16.
At the same stage of last season's competition, City lost to eventual winners Paris St Germain before scraping into the playoffs with a win over Club Brugge.
"In that game in Paris, we were 2-0 up, in that moment PSG were out of the competition, then we lost 4-2 and after, unbelievably, they won the Champions League deservedly," Guardiola said.
"Today we have 13 points, the chance to qualify in the top eight so that is enough argument to be focusing on tomorrow, not on what happened in the past."
The artificial turf at Bodo has brought about a change in City's preparations, with Monday's training session taking place at the Aspmyra stadium.
"Of course it's different. Never, since I am here at Manchester, have I ever trained in the stadium before," Guardiola said.
"But they have to see how the ball bounces, how it is with the short passes, long passes, this kind of stuff.
"Life is never a red carpet, how quickly you adjust to the comfort of situations, you are closer to success."
Midfielder Phil Foden picked up a hand injury against United, with Guardiola saying he had some broken bones, but he will be wearing protection and is available.
Guardiola also spoke about the signing of 25-year-old defender Marc Guehi who joined from Crystal Palace on Monday, a welcome addition to City's injury-hit defence, with Ruben Dias, Josko Gvardiol and John Stones sidelined.
"He is a top central defender. He has the perfect age to play for many years and can play on the right or left," Guardiola said.
"The problems we have at the back, it's really important that he is here. Thanks to the club for bringing him here."