After six straight wins on home turf, Naby Keita’s strike condemned United to their first home defeat since December 19.
"There is no shame in getting beat off Liverpool,” Burn admitted. “Them and City are probably the best two teams in the world at the moment so that's where we want to be so it was a bit of a measure to see how far away we are.
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“The front three, whoever plays out of the five world class players they've got, can cause teams problems.
"[Luis] Diaz is a very special player and was very good. They're well organised and they win even when they're not at their best. They probably weren't at their best [on Saturday], but they keep picking up points."
As a boyhood Newcastle fan, Burn has relished playing at St James’s Park so far and remains positive despite the loss.
“The atmosphere in the dressing room was a bit flat as you'd expect, everyone is positive but no one likes getting beat,” he told The Gazette.
"It was there for us, we could have given them more of a problem than we did but they're one of the best teams in the world.”
He added: “There's not just confidence in the team but the stadium as well. It is a nice place to play at the minute with the atmosphere, all the flags and everything, it's class like and I love playing at home.
"There is no shame in getting beat off Liverpool, we gave them a decent game and we'll go and try and affect City next weekend.”
Sunday will see Newcastle face a trip to another title-challenging side in Manchester City (16:30pm kick-off).
Pep Guardiola’s side currently lead the Premier League by a point and have won each of their last 12 league matches against The Magpies on home turf.