Defoe, 31, has reportedly agreed a £90,000-a-week deal with his new club and leaves Spurs for a fee of about £8million.
The England striker, who has signed a four-year deal with Toronto, said: "Everybody knows how much Spurs mean to me and I will play my heart out for the team and the fans until my last kick for the club. I have had a fantastic time here and the fans have always been amazing to me.
"I am grateful for the opportunity for myself and my family to experience living overseas and for me to play in the MLS with a contract that will take me to the age of 35. I have no doubt I shall be coming back as a fan supporting the team in the years to come, too."
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