Premier League is best in world - Pochettino
The former Tottenham boss, 51, has taken over at Stamford Bridge on a two-year deal with the option of a third.
Chelsea endured a terrible 2022-23 season in which they had three managers and finished 12th in the league.
"It is about delivering from now," Pochettino said at his unveiling. "We cannot tell the people we need six months to create something."
Speaking at his first news conference at Stamford Bridge, he added: "I spoke with the owners in a really good way. They are clever people and I feel good. I am not a coach who needs to ask for power.
"The most important thing I need to show them is to trust in me and the players and the fans can trust my decisions and the way we operate."
Mauricio Pochettino was manager of rivals Tottenham from 2014 to 2019
Pochettino had been linked with a return to Tottenham after they parted company with Antonio Conte in March, but he instead joined their London rivals.
Having started his managerial career with Espanyol before a 16-month spell at Southampton, he then managed Spurs from 2014 to 2019.
He caused ire from his former supporters when he described Chelsea as "the greatest team in England" over the past 10 to 15 years during an in-house interview.
Last season, Manchester City claimed a Treble of Champions League, Premier League and FA Cup and Pochettino said his side need to "believe" they can compete.
"I want to congratulate Pep [Guardiola] on what he has achieved with Manchester City," he said. "It's amazing to see a club gain so much stability with the tools from the manager.
"Chelsea in the last 10, 12 or 15 years have enjoyed a similar achievement. Now, we need to believe that we can also create great things and believe we can compete with Manchester City.
"My target is to win, my aim is to win. Play well is our style, philosophy and culture. If you don't win in a club like Chelsea, you will struggle.
"With the players we have and the strategy to believe. It's about winning, being competitive. And translate this energy to our fans. To create the togetherness, it's difficult, in the Premier League all together we can be close to win again."
Pochettino is Chelsea's sixth permanent manager in five years following the sacking of Thomas Tuchel and Graham Potter earlier this season, with Frank Lampard taking interim charge until the end of the season.
He is also the fourth boss of new owner Todd Boehly's reign after the American took over at Stamford Bridge last July.
Chelsea are undergoing a transformation in their playing squad too - they have spent more than £550m on new players and nine have left this summer including Kai Havertz to Arsenal, Mason Mount to Manchester United and captain Cesar Azpilicueta to Atletico Madrid.
Pochettino said: "I'm not thinking about how many challenges or the most difficult one. The most important thing is to get a balanced squad.
"The plan was to reduce the numbers of players and then create a good dynamic on the training ground. I am not giving players the opportunity to waste time. We need to give our best from the start.
"We are going to have a squad that can deliver."
-- Courtesy of BBC Sport