The 33-year-old attacker joined the Premier League side from Bayer Leverkusen in 2015 and went on to play more than 450 times for Spurs.

In May he lifted the Europa League trophy but he had a poor season overall by his high standards and struggled with a series of leg injuries.

"Before we start the press conference I wanted to say I have decided to leave the club this summer," the South Korean told reporters in Seoul, where Tottenham are on a pre-season tour.

"Respectfully the club is helping me with this decision."

Son, who has scored 173 goals for Spurs, did not say where he intends to go next and cut an emotional figure.

He has been linked with a move to the MLS in the United States.

"It was the most difficult decision I have made in my career. Such amazing memories. It was so hard to make the decision," Son said, flanked by new Tottenham boss Thomas Frank.

"I need a new environment to push myself. I need a little bit of change -- 10 years is a long time. I came to north London as a kid, 23 years old, such a young age.

"I leave this club as a grown man, a very proud man."

Speaking in Korean, Son said that winning a European trophy -- Tottenham's first European crown in 41 years -- played "a big part" in his thinking.

"Winning a title in Europe felt like I had achieved everything I possibly could," he said.

"I spent a lot of time reflecting on whether I wanted to experience football in a different environment, and I had those conversations with myself over and over again."

Frank, who joined Spurs from Brentford in June, paid tribute to the South Korean skipper.

"For me, personally, I would have loved to have worked with this fantastic person and player," said the Dane, who took over from the sacked Ange Postecoglou.

"He is a true Spurs legend in every aspect, one of the greatest players to play in the Premier League."

Spurs will face Newcastle United on Sunday in Seoul, and Son is guaranteed a rapturous reception in front of his home fans.

Spurs have had a fairly quiet summer in the transfer market so far, with attacking midfielder Mohammed Kudus from West Ham their only major acquisition.

Morgan Gibbs-White had looked set to follow from Nottingham Forest but a £60 million move broke down.