Norway striker Erling Haaland smiled broadly but remained tight-lipped about his move from Borussia Dortmund to Manchester City as he joined up with the national squad for their four Nations League matches in June.

The 21-year-old, who scored 22 goals in 24 Bundesliga games in the past season will become a City player on July 1, entered Monday's news conference in Oslo rubbing his hands, but he had little enthusiasm for discussing his club situation.

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"[The last few months] have been tough. This thing, it hasn't been simple, at the same time I have been doing the best that I can for Borussia Dortmund for two and a half years," he told reporters.

"It wasn't easy, but I've done the best I can for the club. I'm ready for four games [with the national team] and that makes me happy."

Norway manager Stale Solbakken opened the news conference by pointing out that Haaland had not been presented by his new club yet, and that the player would not be answering questions about his future there.

City chairman Khaldoon Al Mubarak, however, did not mince his words, saying the Premier League champions had invested in the "best number nine in the world at the right age."

"Haaland, from his early days in Norway and then moving on to Dortmund, has been on our radar for at least four or five years," Al Mubarak said in an interview on City's website.

"He is a very, very unique, incredibly talented striker that I think the whole world has been looking at. I would say every big team in the world wanted [him] to join and we're absolutely delighted that Haaland chose to join Manchester City."

Haaland also described his pain at the death of his agent Mino Raiola on April 30, 10 days before City and Dortmund announced that an agreement had been reached for his transfer.

"It made things different. You can imagine, I don't have to say too much more," Haaland said. "But that's how it is. I can't complain, I like my life, I like where I am. I shouldn't complain."

Haaland explained that he overcame the pressure of months of speculation about his club future by concentrating on what he could control.

"If I can boast a little, if there's something I'm very good at it's focusing, focusing on football and not on things I shouldn't focus on, shutting out everything," Haaland said.

Norway play Serbia and Sweden away on June 2 and June 5, before returning to Oslo to host Slovenia and the Swedes in Nations League Group B4.

Two-time defending Premier League champions Man City are also awaiting the summer arrival of Argentina international Julian Alvarez, who they signed from River Plate in January, but Al Mubarak added that supporters can expect more signings during the upcoming transfer window.

"I can confirm that there will be more players coming in. We are looking to strengthen the team in the areas that we need strengthening," Al Mubarak said. "As you know, every season some players leave, and then we have to continuously refresh the team. Again, we will always look at improving and strengthening.

"I think we've made two very important additions already, but I anticipate we'll be doing a couple more. We'll try to go as fast as we can, but you know how the market goes -- it's not always entirely in our control."

City have won their fourth Premier League title in five years and, although the club are aiming to bolster the squad, Al Mubarak said manager Pep Guardiola would also look for solutions within the academy.

"We're in a different position to the one we were in many years ago," he added. "We have so much talent available within the squad and the academy that when we need something, it's very specific and it's very deliberate."