The 25-year-old was a key performer for Southgate during the World Cup over the summer, with his six goals helping him earn the tournament's Golden Boot award, as well as a fourth-place finish for the Three Lions.
Southgate, who will present the award to the England captain ahead of the UEFA Nations League clash against Spain, believes that Kane's endeavours in Russia has elevated his status in the game.
"Look at the No 9s around the world - Messi and Ronaldo are different players - and I can’t see a better one," said Southgate, as quoted by the Daily Mail.
"As a player, you are always questioned and challenged about the next step. The reason I made him captain is he has that drive to continually improve. That’s what drives the very best.
"They want to continually win, making a difference in the games that matter, winning trophies. That’s what I’ve seen in the last five years working with Harry. I don’t see any signs of that hunger and ambition dwindling. He’s coming into his prime."
Kane has certainly become accustomed to finishing as a competition's top scorer, having already finished as the Premier League top scorer twice in his career in 2015/16 and 2016/17.
While admitting that winning the World Cup Golden Boot is a huge honour, his attention now turns to the next competition, and wants to start the Nations League with a win against La Furia Roja at Wembley.
The Spurs striker said: "I might look back on the Golden Boot at the end of my career with huge pride, telling the story. But it’s about the next step. We are going into every game wanting to win. That starts against Spain."