Sunderland striker Jermain Defoe has re-signed for former club Bournemouth on a free transfer worth £20million.

Defoe, 34, leaves relegated Sunderland to return to the club where he spent a season on loan from West Ham 16 years ago – and he is excited by the challenge ahead.

The England international, 34, who has signed a three-year deal, said: “It’s great to be back. The one thing I can guarantee is goals.”

Defoe said: ‘It’s great to be back and I’m really looking forward to this challenge.

‘When the opportunity came about to return to AFC Bournemouth I just knew it was the right one.

‘It was an easy decision, joining a top team with a top manager. It’s a great place to be.

‘The Bournemouth fans know that every time I pull the shirt on I will give 100 per cent, and the one thing I can guarantee is goals.’

The former Tottenham, Portsmouth, West Ham and Charlton player is seventh on the Premier League all-time goals list with 158 in 468 appearances.

Cherries manager Eddie Howe said: ‘This a huge moment for the football club and another step in the right direction.

‘We want to bring players here who can have a big impact on our continued rise and we believe Jermain fits that as a natural, proven goal scorer.

‘We have known him for a long time, since working with him as a young pro and playing with him. I have followed his career and am delighted to say he is going to be playing for AFC Bournemouth again.’

Defoe is Bournemouth’s second signing of the summer, following the arrival of goalkeeper Asmir Begovic from Chelsea.