Amir Khan declares, "I'm done" - Amir Khan says he will retire at 35 and promises to KO his rival Kell Brook in a grudge match.

AMIR KHAN revealed that he will RETIRE following his grudge match against Kell Brook, but vowed to leave on a high.

With a sell out in Manchester on February 19, the long-standing welterweight rivals will finally settle their differences in the ring.

Khan admitted that the final fight would be his last, but vowed to come out with a knockout.

On Instagram, he said: "I leave the decision to God as to which round I knock Kell Brook out. 100 percent I will win this fight.

"People often ask me what I do after this fight." I'm done, man."

Khan, 35, will be remembered as Britain's greatest fighter - a silver medalist at 17 years old and former unified champion.

Brook, who is also 35, didn't get the same recognition, but was a long-reigning IBF Welterweight title holder with outstanding skills.

He plans to end Khan's legacy by taking on Khan in one fight.

Brook stated that Brook "messed around when we got contracts over our heads."

"Now that we have a date, let us make this fight happen. I want him to show up on February 19, as best as he can.

"The fans have been waiting too much. I have been waiting too long. I am more than willing to prove that I'm the best.

"After this fight Amir will be nothing but a memory."

Brook won the crowning night in 2014, when he took Shawn Porter's title in California.

It's one of the most impressive wins by a Brit on the Road in recent memory.

Brook was also defeated by Gennady and Errol Golovkin at middleweight and Errol Spence Jr. at welterweight.

He believes that this fight will be his best, and his dream fight is on the horizon.

Brook stated, "I'm putting my self through hell. This fight will be remembered by my friends.

"It took years before this grudge match finally got here. Fans have waited for this fight for years.