It has been a mixed week for Manchester City's rivals thus far, with Arsenal thrashing Chelsea 5-0 on Tuesday this week before Liverpool suffered a surprise 2-0 defeat in Wednesday's Merseyside derby at Everton.
Those results mean the Gunners(Arsenal) sit four points clear of Manchester City and Liverpool lead the champions by one, but with two games in hand, the title race is still very much in Manchester City's hands.
They go to Brighton and Hove Albion on today before facing Nottingham Forest on Sunday, and Guardiola still thinks even the slightest slip-up could prove costly.
Asked whether Manchester City need to win their six remaining games to win the title, Guardiola said: "Yes, absolutely. They gave us a chance, with the fact they lost last week to Aston Villa and Crystal Palace.
"But we knew what we had to do before those games, and now we have to win all games so that at the end, we have it in our hands to retain our title.
"Nothing changes. The fact is, we knew what we had to do before, and now nothing has changed."
Guardiola was then asked whether Manchester City are as motivated to win the title as their rivals, having lifted the trophy in five of their seven seasons under him to date.
He said: "I would not be here [if not]. There are so many games, and to be in this position after what we have done in the past, it would not be possible [without the desire].
"We know the difficulty is extreme, and it will remain difficult because we have tough games coming up. We go one game at a time, and we know that if we lose, it will be so tough to retain the title.
"Last Saturday proved the many difficulties we have, especially the schedule and recovery time after the game against [Real] Madrid. The players were unbelievable."
Guardiola hit out at the busy nature of the schedule after Saturday's FA Cup semi-final win over Chelsea, saying he couldn't understand how his players had managed to perform just three days after their penalty shoot-out defeat to Real Madrid.
Those comments have sparked renewed debate about the football calendar, and Guardiola was asked whether elite clubs had a right to complain while organising money-spinning pre-season tours around the globe.
"Yeah, but we have to do it," he said. "We have to pay the salaries of the players and the manager, and the club has fans all around the world who want to see us. They are an income for us.
"It's not easy, but we have to get resources. I would love to say don't go to another continent to play, have another week of holiday, and then train here. But we have to understand the club.
"It's not just Man City. Every club needs those financial resources to be sustainable. Now that we've won a lot, for many years, we have a lot of supporters. That's why it's necessary to do, and you have to adapt.
"But that is not the reason why [he complained]. The reason is that the schedule is so tight. I'm sorry, it's not."