The champions have offered Liverpool the chance to move seven points clear at the summit on Wednesday following a sluggish performance at St James' Park, despite taking the lead after 24 seconds. Guardiola was left to rue the defeat while insisting he won't dwell on the ramifications.
He said: "We knew that we have to win a lot of games because the advantage is not huge. But we have to continue. In football, many things can happen.
"The most important thing is not thinking about the table. We have to play our game, do what we have to do. When it does not happen, you can lose, it happens. In many, many details, it was not our best today.
"We had a chance today to reduce the lead. Tomorrow is a game for our opponent. When you are behind you have to win games and we couldn't do that.
"I know the challenge is big, being in all competitions is what it is. If you want to go up as a club you have to accept that challenge. I prefer to be in that position."
Reflecting on the performance, Guardiola questioned his players' belief and commitment saying: "We didn't have the rhythm that we need to impose our game. Our game was slow, we didn't commit, we didn't find the players who we believed we could find.
"They shot twice. The first was the goal and the second was the penalty. We had the chances but when that happens, everything is open. Congratulations to Newcastle for the victory.
"There are episodes that can change the game, of course, but in general we did not have the rhythm for a Premier League game."