Manchester City signing Kyle Walker says they must overtake former club Tottenham to prove themselves title challengers.

Walker was full of praise for his former club and not only backed Spurs to be a team to beat in the Premier League title race but also a rival to better on the world stage.

"It's a couple of hard games to start off with," he told City TV of the two friendly games in the US.

"But, if we are going to be up there as one of the best teams in the world, we are going to need to challenge the likes of Manchester United, Real Madrid and Tottenham - who have had a couple of fantastic seasons under Pochettino."