US President Joe Biden (center) participates in a trilateral meeting with British Prime Minister Rishi Sunak (right) and Australia's Prime Minister Anthony Albanese (left) during the AUKUS summit on Mar 13, 2023, at Naval Base Point Loma in San Diego California. (PHOTO / AFP)

MOSCOW — Russia said on Tuesday that a joint plan by the United States, Britain and Australia to create a new fleet of nuclear-powered submarines raised questions about nuclear proliferation.

The leaders of the three countries on Monday announced details of the plan as part of their "AUKUS" partnership pact.

US President Joe Biden stressed at Monday's meeting with the British and Australian prime ministers in San Diego that the submarines would be nuclear-powered, not nuclear-armed

Kremlin spokesman Dmitry Peskov told reporters: "There are a lot of questions here related to the problem of non-proliferation. Here we need special transparency, and we need to answer the questions that arise."

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US President Joe Biden stressed at Monday's meeting with the British and Australian prime ministers in San Diego that the submarines would be nuclear-powered, not nuclear-armed.

"These boats will not have nuclear weapons of any kind on them," he said.

To date no party to the nuclear Non-Proliferation Treaty (NPT) other than the five countries the treaty recognises as weapons states has nuclear-powered submarines. The vessels can stay underwater for longer than conventional ones and are harder to detect.

Russia's own Pacific Fleet has 17 submarines including three ballistic missile subs that are part of its strategic nuclear deterrent, according to the latest annual report by the International Institute for Strategic Studies.

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Australia says it will be unable and unwilling to use the fuel in its submarines to make nuclear weapons since the vessels will have "welded power units" containing nuclear material that would need chemical processing for use in an atom bomb, and Australia does not have or want facilities that can do that.

The AUKUS countries and the International Atomic Energy Agency (IAEA) say the NPT allows so-called marine nuclear propulsion provided necessary arrangements are made with the IAEA.