A former US national security agency chief has called for an expansion of shared technology with Australia amid a power shift and a more assertive China. 

The US, UK and Australia need to use the trilateral AUKUS alliance to create a fundamental shift in the nations’ capabilities as America’s technological supremacy lags, former four-star admiral Michael Rogers says.

“We are not optimised for the world of the 21st century. The structures in the US we created all reflect the time when the US was the leader in technology,” Mr Rogers told the National Press Club on Friday.

“AUKUS is about much more than just acquisition. 

“We need to make AUKUS an engine for innovation. We should not be using this to reinforce the status quo. We should be using this as a vehicle to enhance a better outcome potential using different approaches.”

Mr Rodgers, who headed the National Security Agency and US Cyber Command under presidents Barack Obama and Donald Trump, also called for greater technology sharing in light of Canberra’s acquisition of nuclear-powered submarines through AUKUS.

“The undersea domain is the one area arguably, from the US perspective, where we believe we have and can sustain supremacy,” he said.

“We have been very careful about sharing technology within that environment because we think that’s a core warfighting and operational advantage for us.

“If we’re willing to share that kind of technology with Australia, could you explain why we have all these other restrictions on things that are much lesser to me in terms of risk?”

Ahead of the address, Mr Rogers told the ABC shifting priorities had also resulted in a renewed Indo-Pacific pivot.

“For a long time, particularly the post 9/11 environment, the US was dealing with a counterterrorism challenge that was not centred in the Indo-Pacific region,” he said.

“That focus took resources, time, attention, leaders’ decision bandwidth. We shifted that focus.

“But we have to acknowledge circumstances have changed. The Indo-Pacific region remains a cornerstone for the future for this world and we need to be fully integrated.”

Earlier on Friday, US ambassador to Australia Caroline Kennedy told reporters in Sydney she would focus on regional security, economic engagement and climate change in the face of expanding Chinese influence.

“Everybody is so excited about working together in the Quad and in the Pacific,” she said after landing.

“China certainly has a big presence here in the region but our partnership is what I’ll be focused on. There’s a big agenda and I can’t wait to get started.”

Despite the US ambassador post to Australia remaining vacant for around 18 months, Ms Kennedy said the Pacific has drawn the focus of Washington.

“It’s certainly a big focus now. This is a critical area in the region,” she said.

“The US need to do more. We’re putting our embassies back in, and the Peace Corps is coming and USAID is coming back.

“We haven’t been there for a while but that’s all tremendously positive. The US and Australia working together will make a big, big impact.”

Ms Kennedy will formally present her credentials to the governor-general on Monday.