Steve Smith, Jake Fraser-McGurk omitted as Australia unveils T20 ...

Mitch Marsh has been appointed as Australia's men's Twenty20 captain, with the all-rounder set to lead a squad to the World Cup that does not include Steve Smith or Jake Fraser-McGurk.

Selectors officially confirmed Marsh's appointment on Wednesday, succeeding Aaron Finch after several players juggled the role in the past 18 months.

After captaining Australia on recent tours, Marsh's first full-time appointment will be at next month's World Cup in the Caribbean and the United States.

He will go there without Smith or Fraser-McGurk, with the pair overlooked in Australia's provisional 15-man squad.

Smith's axing marks the first time he has not been picked for an Australia squad on form in more than a decade.

He last missed a World Cup in any format in 2012.

The 34-year-old had hoped to open in this year's tournament, but had always been at long odds given the country's depth in that position.

Fraser-McGurk's absence is more controversial, given his stunning form in the Indian Premier League.

The opener's strike rate of 233.33 is the best of any player in the tournament with 100 or more runs, after bursting onto the scene for Delhi.

But that has not been enough to crack Australia's side, with Travis Head and David Warner most likely to open at the World Cup.

Marsh is expected to bat at number three in Australia's best XI, with Glenn Maxwell at number four.

There had been the option of batting Fraser-McGurk lower down the order as a finisher, but Tim David has instead held his spot in the squad.

Marcus Stoinis is also included as an all-rounder who can act as a finisher, while Australia has selected two wicketkeepers in Matt Wade and Josh Inglis.

Ashton Agar has been named alongside Adam Zampa as a second spinner on wickets expected to turn, while Nathan Ellis is the fourth quick behind the regular three.

"The batting options available allow a tailored approach to each venue and opponent," chief selector George Bailey said.

"Steve Smith, Matt Short, Jason Behrendorff, Aaron Hardie, Spencer Johnson and Xavier Bartlett were all part of long conversations, along with several others, including Jake Fraser-McGurk who is yet to play T20 International cricket but continues to impress and is developing rapidly."

Officials have until May 25 to alter the squad without ICC approval. 

Victory in the upcoming tournament would make Australia world champions across all men's and women's formats.

AUSTRALIA'S PROVISIONAL 15-MAN SQUAD FOR T20 WORLD CUP

Mitch Marsh (c), Ashton Agar, Pat Cummins, Tim David, Nathan Ellis,  Cameron Green, Josh Hazlewood, Travis Head, Josh Inglis, Glenn Maxwell, Mitchell Starc, Marcus Stoinis, Matt Wade, David Warner, Adam Zampa.

AAP