OLYMPIC gold medallist Oleksandr Usyk will harness the star power of his rematch with Briton Anthony Joshua to raise relief funds for his native Ukraine, the unified heavyweight champion told Reuters.

Usyk and Joshua are expected to fight later this year, though a date and location have not been determined.

Usyk joined Kyiv's territorial defence battalion after Russia began its invasion in February but received permission weeks later to leave the country and prepare for a rematch against Joshua. He did not disclose his next location.

He told Reuters he will use the high-profile fight with Joshua to raise funds for Ukraine with a collection of 2,000 non-fungible tokens, or NFTs, released through Blockasset.co, hoping to generate upwards of $1 million.

NFTs are a type of crypto asset that uses blockchain to record the ownership of digital files such as an image, video or piece of text.

The funds raised will go to the fighter's charity, Usyk Foundation, to help Ukrainians.

"Many people in Ukraine are now seeking help," Usyk said, via an interpreter. "We think that as soon as it's released, many people will actually receive this help - people who actually need it."

The NFTs will be released ahead of the fight and designed by artist Dosbrak, who has previously worked with former UFC two-weight champion Connor McGregor and former heavyweight champion Mike Tyson.

Sweetening the deal, Usyk said two tickets to his fight with Joshua will be handed out at random to one of the NFT buyers.

The southpaw boxer was in London on a promotional visit when Russia's invasion of Ukraine began on Feb. 24. Usyk flew to Warsaw before driving 500 miles (800 km) to Kyiv to be with his family, as he was unable to fly home directly.

Russia sent tens of thousands of troops into Ukraine on Feb. 24 in what it called a "special operation" to degrade its military capabilities and root out what it calls dangerous nationalists. Ukrainian forces have mounted stiff resistance and the West has imposed sweeping sanctions on Russia in an effort to force it to withdraw its forces.

Usyk said he plans to return to Ukraine immediately after the fight with Joshua, which he said he took on to "support the spirit" of Ukraine.

The 35-year-old put on a masterclass to seize the WBA, WBO, IBF and IBO belts in September, when he dethroned former world heavyweight champion Joshua in front of a sell-out crowd at Tottenham Hotspur Stadium. 

"It's going to be different," said Usyk, who expects Joshua to prepare something new this time around.

He will need every tool in his arsenal to come out on top again and said the Briton should be prepared to have a few tricks thrown his way.

"I cannot reveal everything. I cannot open my cards," he said. "One of the hints is that I'm going to change my stance or my position."