The Belgium international completed his transfer to United from Aston Villa earlier this week, signing a five-year contract after helping his country reach the quarter-finals of the 2026 FIFA World Cup.
The experienced midfielder arrives after successful spells with Anderlecht, Monaco, Leicester City and Aston Villa, bringing leadership and top-level experience to Michael Carrick's squad.
Speaking after his arrival, Tielemans said United's direction and the quality already within the team made the decision an easy one.
"I think it's a great step up for myself," he said. "The club is in a great place, and I feel like there is a lot of ambition inside the club.
"Inside the team, there's a lot of quality and I feel like this is a good step for me to push on and hopefully win many, many titles with the club.
"I'm very happy and very excited to start, and to meet my team-mates and be on the pitch together."
At 29, Tielemans believes he is entering the next stage of his career and feels United is the perfect place to continue developing while competing for silverware.
"I have big experience, 29 years old and I'm ready to push on and make the next step in my career," he said. "That's why this is the perfect club for me.
"They want to win and, hopefully, be really good on the pitch, so that's why I chose to come here."
Tielemans is also expected to add leadership to Carrick's dressing room. He captained Anderlecht in European competition while still a teenager and was handed the Belgium captaincy ahead of established stars Kevin De Bruyne and Thibaut Courtois during the World Cup.
The midfielder believes leading a team comes naturally to him and hopes to bring those qualities to Old Trafford.
"Being in that leadership role has been really good for me," he said. "I find myself naturally in that and, hopefully, I can bring that into the team."
Slovenian referee Slavko Vincic has said he was overwhelmed with emotion after learning he had been chosen to officiate Sunday's 2026 FIFA World Cup final between Spain and Argentina at MetLife Stadium.
Pep Guardiola has revealed he has no plans to rush back into football after leaving Manchester City, saying he wants to enjoy life away from the game and spend more time with his family.
Anthony Gordon admitted England's heartbreaking World Cup semi-final defeat to Argentina will stay with him for some time, saying he believed the Three Lions were finally destined to end their decades-long wait for glory.
Dominik Szoboszlai has reportedly committed his long-term future to Liverpool after signing a new contract that will keep him at Anfield until June 2031.
