Marine Corps Commandant David Berger said Washington and Canberra would need "everything in the cupboard to prevent a conflict".

"We can't slow down, we can't back off, we can't get comfortable," he told an Australian Strategic Policy Institute briefing.

"The risk then is the other side moves a half step and we've lost the deterrent value that we're after in the first place."

His comments come after a four-star US Air Force general wrote a memo warning of an all-out war with China within the next two years.

The Pentagon sought to distance itself from the comments, saying they did not reflect the department's view.

Defence Minister Richard Marles said Australia would continue to push for the maintenance of the status quo in the Taiwain Strait and pursue a reduction in tensions.

"The starting point of that is to make sure that we are active in our diplomacy and that's what we've been doing," he told ABC radio.

"But it's also about making sure that we get the hard power equation right from an Australian point of view, and we're doing that as well."

The government is poised to announce its choice of a US or British-designed nuclear-powered submarine as part of the trilateral AUKUS agreement between the three nations in March.

Mr Marles hosed down speculation the submarine delivery timeline would be delayed after the US suddenly shut down four repair docks for maintenance.

"We certainly understand the size of the challenge for all three countries and there is an ambitious timeline that will be articulated when this announcement is made," he told Nine's Today program.

Mr Marles and Foreign Minister Penny Wong are meeting their counterparts in London, where the future of the AUKUS alliance is on the agenda.

"Australia sees our investment in our future defence capabilities as essential for deterring conflict and maintaining a strategic balance in the Indo-Pacific," Senator Wong said.

"Our historic AUKUS partnership with the United Kingdom and the United States will help us maintain our capability in the Indo-Pacific."

The defence minister is also due to meet his US counterpart Lloyd Austin later this week.

Beijing's mouthpiece the Global Times branded AUKUS "a paper tiger with no real sense of realistic deterrence".

It also took aim at the US for trying to establish a "global military alliance" aimed at "suppressing and containing China".

"In the construction of this new alliance system in the Asia-Pacific region, the biggest target is China," it said.

During their UK trip the Australian ministers will also meet new prime minister Rishi Sunak to discuss security concerns, and visit Australian and British troops training Ukrainian soldiers as part of an international effort to boost Kyiv's defences.

The duo will also visit Portsmouth's dockyards.

Australian Associated Press