Anthony Joshua will fight in the US for the first time when he defends his IBF, WBA and WBO world heavyweight titles against Jarrell Miller on 1 June.
Joshua, 29, will take on Miller at Madison Square Garden in the undefeated American's home city of New York.
Miller, with 23 wins and a draw, has never fought for a world title.
The 30-year-old will almost certainly be the heaviest opponent Joshua has faced as a professional having weighed 22st 7lbs in his last contest.
That is almost five stone heavier than what Joshua weighed in at ahead of his victory over Alexander Povetkin in September.
Miller - nicknamed 'Big Baby' - won 20 of his fights by knockout but Joshua represents a huge step-up in class.
Joshua said: "I am heading to the Big Apple and I plan to embrace the culture and leave with an appetite for more.
"It has been an honour and a blessing to fight at some of the best venues in the world and at home in the UK, not least Wembley Stadium, but the time has come to head across the Atlantic and defend my heavyweight titles in the USA.
"I am looking forward to taking on another challenge with a good boxer and a brilliant talker. It will be an exciting fight. I will leave nothing to chance and plan on dismantling Miller in style to make my mark."
Miller added: "AJ is making a huge mistake coming over here to fight me in my own backyard - he'll be leaving New York empty-handed.
"This is the fight that I've been chasing all my life and on 1 June I'm going to achieve the thing I was born to do."
The best of decreasing options
Miller made his debut in a bout at a restaurant 10 years ago and, while he has wins over the likes of compatriot Gerald Washington and Poland's Mariusz Wach to his name, most UK sports fans will probably know little of his career.
Joshua has been left with few options given fellow Briton Tyson Fury and WBC champion Deontay Wilder are set for a rematch, while Dillian Whyte has openly criticised the financial offer Joshua's team presented him with for a 13 April bout.
Joshua had Wembley Stadium booked for the date where he had hoped to face Wilder, but has scrapped the booking in favour of a US debut.
"Things happen, boxing politics," he said. "We had to branch out and look for other options."
A contest in the US has been seen by Joshua's advisers as a chance to enhance his global appeal.
Britain's Lennox Lewis boxed at Madison Square Garden three times, while greats such as Muhammad Ali, Evander Holyfield and Sugar Ray Robinson have also competed there.
There will undoubtedly be criticism of the move, given the public clamour for him to face Fury or Wilder in a bout that would unify all four belts.
Negotiations have repeatedly failed with Wilder, while the offers sent to both Fury and Whyte were deemed insufficient.
Wilder and Fury are now set for a rematch following their 1 December draw, while Whyte will fight in the UK in April or May.
Miller was not even listed by Joshua when he asked fans to vote on his next move in September, when 53% of respondents wanted a Wilder fixture and 42% called for Fury.
But the American - who has clashed with Joshua at a news conference before - can at least be expected to provide memorable sound bites when promoting the fight and give Joshua chance to increase his profile in the lucrative US pay-per-view market.