Deontay Wilder

WBC champion Wilder is yet to agree to a unification fight with Joshua, who is aiming to hold all four of the major heavyweight belts. 

The lengthy negotiations have once again stalled after delays in the American's camp returning the contract they were sent by Hearn.

Now, the World Boxing Association (WBA) has ordered the Briton to sign for a mandatory title defence against Povetkin within 24 hours, and Hearn believes the governing body has run out of patience.

The unbeaten fighters have been on a collision course for some time, particularly since Joshua defeated Joseph Parker to add the WBO strap to his WBA and IBF belts.

However, despite plenty of back-and-forth verbal sparring, a deal has yet to materialise and Hearn, Joshua's promoter, recently suggested that an agreement to fight Alexander Povetkin was close and the Wilder clash would have to wait until February 2019.

Unbeaten knockout merchants Joshua (21-0) and Deontay Wilder (40-0) have seemingly been on a collision course for some time, particularly since the former beat Joseph Parker to add the WBO title to his WBA and IBF belts.

Negotiations with WBC holder Wilder and his camp have appeared fractious at best, but a breakthrough appears on the horizon.

However, Joshua will likely fight WBA mandatory challenger Alexander Povetkin first, with an announcement expected before the end of the week.

A unification bout with WBC champion Wilder has been touted for WBA, IBF and WBO titleholder Joshua, who claimed the latter belt with a unanimous decision over Joseph Parker last month.

A clash between the two unbeaten boxers is the fight everyone wants to see and on Wednesday, American Wilder announced he had something in the mail for Joshua – a $50m offer.

"I got something special for you," Wilder tweeted. "And by the way, all the money's in the bag."

Joshua vowed to knock WBC champion Wilder "spark out" after beating Joseph Parker in Cardiff on Saturday to add the WBO belt to his IBF and WBA straps.

Finkel said the Wilder camp are prepared to come to an agreement to face the Briton, with reports that a two-fight deal for bouts in the UK and the United States is on the cards.

"We are really glad that Anthony Joshua said for the first time, 'I will fight Deontay next...' and we believe he is a man of his word. Deontay accepts the challenge," Finkel told The Daily Telegraph.

The highly-anticipated bout will see Joshua and Parker put their IBF, WBA Super, IBO and WBO belts and unbeaten records on the line, as both fighters aim to become the first undisputed heavyweight champion since Lennox Lewis in 1999.

Many pundits out of the UK believe Joshua's size and skill will prove too much for Parker at the Principality Stadium on April 1 (NZ time), but Wilder has a different perspective.

Speaking to Andrew Gourdie and Jim Kayes on RadioLIVE's Sunday Sport, Wilder issued a warning not to be deceived by the Briton's chiselled physique.

In taking the fight with fellow unbeaten fighter Ortiz, Wilder has accepted what is widely considered his greatest test yet.

He will be making the sixth defence of his title on March 3 having in November stopped Bermane Stiverne, when a match-up with Ortiz was cancelled after the 38-year-old Cuban tested positive for banned substances in a drugs test.

Ortiz avoided a ban after the WBC found he had taken diuretics for high blood pressure, although he was fined.

The fight will be Wilder's seventh defence of the WBC heavyweight world title.

The 32-year-old American, who last fought in November when he beat Haitian-Canadian Bermane Stiverne with a first-round knockout to retain his WBC heavyweight title, was arrested in Alabama last June.

Wilder, who received a 30-day suspended sentence and two years of probation on Friday (NZ time), was ordered to perform the community service at a local YMCA.

"We respect the court's ruling. Of course we were hoping a dismissal would be granted," Wilder's lawyer, Paul Patterson, said in a phone interview.

WBA and IBF heavyweight champion Joshua is 20-0, all by knockout, following his win over Carlos Takam in Cardiff in October.

Last month, Wilder retained his WBC crown by flooring Bermane Stiverne in the first round to move to 39-0, and Joshua's promoter Eddie Hearn reportedly held talks with the American's representatives about a potential meeting next year.

Joseph Parker, the WBO champ, is also in the mix for a unification bout with Joshua in 2018, and the New Zealander is happy to settle for a 35 per cent share of profits - a notion Wilder will not entertain.

Eddie Hearn, Joshua's promoter, flew out to the United States last week for talks with WBC heavyweight champion Wilder's promoters over a unification fight.

Hearn has also been in touch with Joseph Parker over a potential fight with the WBO strap holder next year.

IBF and WBA champion Joshua is eager to do battle with Wilder, but only if the right deal can be struck.

Speaking courtesy of Sports Tonight/Dubai Eye 103.8, Joshua said when asked if the Wilder fight is the one he wants next year: "Yeah why not?