US warns Australia against joining treaty banning nuclear weapons

The US has warned Australia against joining a landmark treaty banning nuclear weapons, saying the agreement could hamper defence arrangements between the US and its allies.

But New Zealand said it was “pleased to observe a positive shift” in Australia’s position in a United Nations vote and “would, of course, welcome any new ratifications as an important step to achieving a nuclear weapon-free world”.

The comments follow the Albanese government shifting Australia’s voting position on the treaty on the prohibition of nuclear weapons to “abstain” after five years of blanket opposition by the Coalition government.

The relatively new treaty imposes a blanket ban on developing, testing, stockpiling, using or threatening to use nuclear weapons – or helping other countries to carry out such activities. But so far it has been shunned by all of the nuclear weapons states and many of their allies.

The US embassy in Canberra said the treaty “would not allow for US extended deterrence relationships, which are still necessary for international peace and security”.

That is a reference to Australia relying on American nuclear forces to deter any nuclear attack on Australia – the so-called “nuclear umbrella” – even though Australia does not have any of its own atomic weapons.

The embassy said the treaty also risked “reinforcing divisions” within the international community.

“While the United States understands and shares the desire to advance nuclear disarmament goals, we do not support the treaty on the prohibition of nuclear weapons,” a spokesperson for the US embassy told Guardian Australia.

“The United States does not believe that progress toward nuclear disarmament can be decoupled from the prevailing security threats in today’s world.”

The comments are a sign of the pushback Australia faces from its top security ally if it gets closer to signing and ratifying the treaty – although that still seems distant.

New Zealand said it welcomed “constructive developments in Australia’s approach” to the treaty, including the shift from opposing a NZ-backed resolution on the topic at the UN general assembly first committee last month.

New Zealand’s minister for disarmament and arms control, Phil Twyford, has met with Australian representatives.

A spokesperson for the Ministry of Foreign Affairs and Trade said New Zealand continued to urge all countries that were not yet a party to the treaty to sign and ratify it “at the earliest opportunity”, while acknowledging it was “for Australia to determine its position”.

The Australian prime minister, Anthony Albanese, has been involved in advocacy against nuclear weapons and has described them as “the most destructive, inhumane and indiscriminate weapons ever created”.

Albanese moved the motion at Labor’s 2018 national conference backing the TPNW, saying the task would not be easy or simple but it would be “just”.

The treaty now has 91 signatories, 68 of which have formally ratified it, and it entered into force last year.

Sign up to Guardian Australia's Morning Mail Free daily newsletter Our Australian morning briefing email breaks down the key national and international stories of the day and why they matter Privacy Notice: Newsletters may contain info about charities, online ads, and content funded by outside parties. For more information see our Newsletters may contain info about charities, online ads, and content funded by outside parties. For more information see our Privacy Policy . We use Google reCaptcha to protect our website and the Google Privacy Policy and Terms of Service apply.

Labor’s 2021 national platform committed the party to signing and ratifying the treaty “after taking account” of several factors, including the need for an effective verification and enforcement architecture and work to achieve universal support.

These conditions suggest the barriers to actually joining the treaty may still be high.

But campaigners have welcomed Albanese’s comments over the weekend that characterised the very existence of nuclear weapons as a security threat, rather than espousing deterrence.

The prime minister told the Australian newspaper that the threat by the Russian president, Vladimir Putin, to use tactical nuclear weapons “has reminded the world that the existence of nuclear weapons is a threat to global security and the norms we had come to take for granted”.

Gem Romuld, the Australia director of the Nobel peace prize-winning International Campaign to Abolish Nuclear Weapons, said that framing was notable.

“In contrast to the previous government, prime minister Albanese clearly understands that nuclear weapons undermine global security, and that pursuing disarmament is of paramount importance,” Romuld said.

“It’s no surprise the US doesn’t want Australia to join the ban treaty but it will have to respect our right to take a humanitarian stance against these weapons.”

Romuld raised concerns that the plans for hosting of US B-52 aircraft in Australia “could escalate regional tensions or involve nuclear weapons, which Australia has committed not to ‘station’ under the South Pacific Nuclear Weapons Free Zone”.

Indonesia’s ambassador, Siswo Pramono, said Australia’s positive shift on the treaty would “give encouragement to others to believe that we are on the right path” in seeking a world free of nuclear weapons.

Australia continues to pursue closer security and defence cooperation with the US, including plans to acquire nuclear-powered but conventionally armed submarines under the Aukus agreement, which also includes the UK.

The defence minister, Richard Marles, told the Submarine Institute conference in Canberra on Tuesday that Australia must “make sure that we are able to be good nuclear stewards from cradle to grave” to secure international acceptance of Aukus.