BSS/AFP) - Australia and the United States announced Saturday the nations will "streamline" the AUKUS agreement regarding its purchase of nuclear-powered submarines, which will no longer include any new vessels.

The two nations met at Singapore`s Shangri-La Dialogue, which brings together top defence officials and experts from about 45 countries.

Under the 2021 AUKUS deal, Australia is expected to receive at least three of so-called "Virginia-class" nuclear-powered submarines from the United States within 15 years.

In a joint statement from Australian deputy prime minister Richard Marles, US Minister for Defence Pete Hegseth, and the UK Secretary for Defence John Healey the trio confirmed the tweak to the submarine agreement.

"The deputy prime minister and secretaries welcomed the proposed approach to streamline Australia`s acquisition of Virginia-class submarines (VCS), simplifying supply chain management, operational and maintenance requirements, and maximising cost efficiencies," the statement said.

"This approach would enable Australia to acquire three in-service VCS in lieu of a mixture of new and in-service VCS variants."

The US Navy has 24 Virginia-class vessels but American shipyards are struggling to meet production targets set at two new boats each year.

In the United States, critics questioned why Washington would sell nuclear-powered submarines to Australia without stocking its own military first.

Australia had been expecting to receive two used and one new Virginia-class submarine.

The AUKUS submarine programme lies at the heart of Australia`s defence strategy and could cost up to US$235 billion over 30 years, according to government forecasts.