The Spaniard, whose new contract expires in 2021, had one year left to run on his previous deal which he signed upon arrival from Bayern Munich in June 2016.
"I'm so happy and excited".
Manager Guardiola said now was not the time for looking ahead to see if they could improve on their league performance next term.
'I enjoy working with our players every day and we will try to do our best together in the coming years. "I like a lot how they play".
Starting out in top-flight management in 2008, Guardiola spent four years overhauling Barcelona - winning three Spanish league titles and the Champions League twice among 13 honors.
Tillerson warns of 'crisis of ethics and integrity' in US
Trump replaced Tillerson with former CIA Director Mike Pompeo, who is markedly more hawkish than Tillerson, particularly on Iran. Tillerson was criticized for his failure to fill rank-and-file jobs, his perceived aloofness and failure to maintain alliances.
Ebola begins reaching cities in DRC
Since then, an experimental vaccine has been developed, and 4,000 doses have arrived in the Congo, with thousands more to follow. The World Health Organization (WHO) estimates 23 deaths in DRC in recent weeks were linked to Ebola, which has no proven cure.
Trump cautious as NKorea threatens to cancel summit
On one board will be the future of North Korea's nuclear weapons programs, what Trump came to negotiate. In South Korea, the bolt from the blue did not seem to dent popular optimism.
That says something about how relatively unimportant a win at Wembley is, given there wouldn't be much debate if United had the offer of the Premier League title on the table instead.
Second, but some way off Manchester City in the season just gone, Manchester United will once again be closest challengers for the Premier League title. In doing so he has embodied the passion and commitment we all have for the Club.
They ended the season with the most points, most goals, most wins, best goal difference and biggest points-winning margin of any title-winning side, along with a host of other records.
Pep Guardiola has revealed the only business Manchester City are planning for the summer transfer window is to find a midfield replacement for Yaya Toure and perhaps buy another forward.
Executive Vice Chairman Ed Woodward said talk of the creation of a 24-team Club World Cup tournament illustrated the importance of the game to broadcasters.
Guardiola joined Man City at the start of the 16-17 season, and went trophy-less for the very first time in his career, calling the season a "failure". "Having Pep committed to Manchester City for the next three seasons gives us the stability to be able to continue to improve and bring more success to the club".