"We know the combination of Olympic and America's Cup sailing complement each other," Burling said.
"It creates a really high-performance environment across all areas of sailing for us to push ourselves and be at the top of our game," he said.
Tuke said it was not a decision made lightly.
"Representing your country at Olympic level is the highest honour, and we are both incredibly focused on defending the Cup for New Zealand as part of Emirates Team New Zealand. We wanted to ensure we could give both campaigns everything we've got."
Both Burling and Tuke had the support of Emirates Team New Zealand and Yachting New Zealand with Yachting New Zealand high-performance director Ian Stewart looking forward to having them back in the 49er.
"They are special sailors and will strengthen our goal of winning at least three medals in Tokyo but, more than that, their experience and leadership will have a massive impact on the ongoing development of the NZL Sailing Team," Stewart said.
Emirates Team New Zealand chief operating officer Kevin Shoebridge was "happy to have Peter and Blair back as part of the team dedicated to the defence of the America's Cup".
"Once again, we're fully supportive of them integrating the Olympic 49er campaign with America's Cup commitments," Shoebridge said.
"Collectively we are an incredibly strong and talented team that is focused on defending the America's Cup and that allows our core sailing team including Peter, Blair as well as Andy Maloney and Josh Junior to remain in peak sailing condition running parallel Olympic campaigns."
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