Australian Prime Minister Anthony Albanese said that "nowhere on Earth is safe" after remote island territories belonging to Australia were singled out for new U.S. tariffs.

Among countries and territories listed in U.S. President Donald Trump's announcement of sweeping new tariffs in Washington on Wednesday local time were the Australian territories of the Heard and McDonald Islands, and Norfolk Island.

The Heard and McDonald Islands -- an uninhabited territory in the Indian Ocean, around 6,000 km southwest of Australian capital Canberra and some 1,500 km to the Antarctica -- was specified as being subject to Trump's baseline 10 percent tariffs.

Norfolk Island -- about 1,900 km northeast of Canberra in the South Pacific Ocean with a population of about 2,000 -- was hit with a 29 percent tariff, which the U.S. administration said was in response to a 58 percent tariff it faced from the island.

Responding to the tariffs on Thursday, Albanese said he was "not sure" why Norfolk Island had been singled out.

"I'm not quite sure that Norfolk Island, with respect to it, is a trade competitor with the giant economy of the United States," he said.

"But that just shows and exemplifies the fact that nowhere on earth is safe from this."

Authorities on Thursday night confirmed that Norfolk Island had no known exports to the U.S., with tourism its main industry.

"I've got no idea why Trump has given us a tariff," Leah Honeywood, Norfolk Island's Chief Magistrate, told the Australian Financial Review.

"If any export is done, it's been on a personal level. Our industry is tourism -- there's no industry that exports to the U.S.," he added.

Norfolk Island has been an Australian territory since 1914 and the Heard and McDonald Islands since 1947.

Christmas Island, another Australian territory in the Indian Ocean near Indonesia with a population of about 1,600, was also singled out for a baseline 10 percent tariff, as was the nearby small archipelago of the Cocos, or Keeling, Islands, which has been an Australian territory since 1955.