Britain and Australia denied waging a new Cold War with China after their new defence pact with Washington triggered anger from Beijing.
China said the three-way Aukus alliance was an “irresponsible act”, which would damage regional stability and intensify an arms race in the Indo-Pacific.
But the tie-up was viewed more positively by other regional powers including Singapore, Japan and New Zealand.
Unveiled on Wednesday, the pact will give Australia nuclear-powered submarines and the country will co-operate more closely with London and Washington.
The UK, US and Australian leaders did not mention China by name in their initial announcement, but Beijing swiftly took issue with the pact.
The agreement “seriously undermines regional stability and intensifies the arms race”, Foreign Ministry spokesman Zhao Lijian said on Thursday.
He said the three allies should “abandon their outdated Cold War zero-sum thinking” or risk “shooting themselves in the foot”.
UK Prime Minister Boris Johnson sought to play down tensions on Thursday, telling Parliament that the arrangement was not designed to confront China.
The alliance “is not intended to be adversarial towards any other power,” he said. He told MPs that the pact would help to "safeguard the peace and security of the Indo-Pacific”.
Australian Prime Minister Scott Morrison opened the door to talks with Chinese leader Xi Jinping and said any Chinese retaliation would be unjustified.
Canberra has clashed with Beijing on a series of issues, including trade, cyber activities and the coronavirus pandemic, but Mr Morrison said their regional aims should be the same.
“I believe and hope we would both share the same objective of a peaceful Indo-Pacific,” he said.
“It is not an uncommon thing for countries to take decisions in their own strategic interests and to build up their defence capabilities. China makes the same decisions, as do other countries within our region.”
Washington signalled that it would seek to deepen its ties with other Indo-Pacific nations such as India, Vietnam and Japan.
US President Joe Biden will next week meet fellow leaders from the Quad, a separate grouping consisting of America, India, Japan and Australia.
Benjamin Haddad, the head of the Europe Centre at the Atlantic Council think tank, said the alliance was a signal to China that its military build-up was being taken seriously as far away as Europe.
He said the defence alliance was necessary to counter China’s high-tech military capabilities in the region.
“The attack submarines we are helping Australia to build are tailor-made for destroying enemy warships,” he said.
“These are exactly the capabilities we need in the Indo-Pacific to shore up deterrence and defence against China.”
In Tokyo, the pact was welcomed by Japan’s Chief Cabinet Secretary Katsunobu Kato, who said the country was keen to co-operate with allies.
“Strengthening security and defence co-operation between the US, Britain and Australia is important for peace and security in the Indo-Pacific,” he said.
Singapore said it had long-standing ties with the three countries and hoped their alliance would contribute to peace and stability.
New Zealand’s Prime Minister Jacinda Ardern said her country was not approached to join the pact, and would not expect to be because of its opposition to nuclear-powered vessels.
“I am pleased to see that the eye has been turned to our region from partners that we work closely with,” she said. New Zealand is part of the Five Eyes intelligence alliance, which also includes Canada.
One country enraged by the decision was France. The deal spells the end of a submarine contract that Australia had signed with a French firm.
Like Britain, France and the EU have sought to position themselves as major players in the Indo-Pacific, but the deal leaves Paris out in the cold.
French Foreign Minister Jean-Yves Le Drian described the move as a stab in the back. “This is not something allies do to each other,” he said.
The EU offered a cool response. European Commission spokesman Peter Stano said the bloc was not invited to take part.
“The EU was not informed about this project or about this initiative and we are in contact with the partners to find out more,” he said.
Brussels presented its own new Indo-Pacific strategy on Thursday. "We must survive on our own, as others do," EU foreign affairs chief Josep Borrell said as he unveiled it. "I understand the extent to which the French government must be disappointed."