Defence Secretary John Healey declared Britain is ready to fight alongside Australia in the Pacific should it ever be needed.
Healey was alongside Australia's Deputy Prime Minister Richard Marles on board the HMS Prince of Wales in Darwin as the UK joins war games with its allies.
The Defence Secretary was asked what Britain was doing to assist countries is tensions in the region were to escalate.
Healey told media: "If we have to fight, as we have done in the past, Australia and the UK are nations that will fight together."
"We exercise together and by exercising together and being more ready to fight, we deter better together," he added.
He further said the UK would prefer Indo-Pacific disputes to be resolved "peacefully" and "diplomatically".
"We secure peace through strength, and our strength comes from our allies," Healey said.
Deputy Australian Prime Minister Richard Marles, Foreign Secretary David Lammy, Australian Foreign Affairs Minister Penny Wong and Defence Secretary John Healey in Sydney
|REUTERS
China maintains sovereignty over Taiwan and President Xi Jingping hasn't ruled out the use of force in reunifying Taiwan.
The government in Taiwan rejects China's claim.
Experts have warned that a Taiwan invasion could bring countries across the world into a conflict.
Healey recognised that "threats" were increasing in the region with China seizing contested reefs.
HMS Prince of Wales | GETTYChina has also been accused of intimidating its neighbours.
However, Australia has had a more cautious approach when speaking about a conflict.
Australian Prime Minister Anthony Albanese refused to comment on whether the country would join the fight against China if a conflict eventuated.
It comes after Albanese met with Jingping in Shanghai middway through this month.
According to the Department of the Prime Minister and Cabinet's website, Albanese finished his second official visit to China which marked a "further step forward in stabilising relations between our countries".
"The Prime Minister met leading businesses from Australia and China to discuss deepening trade and business ties, including new markets and innovation," the statement continued.
Healey's visit to Australia, alongside Foreign Secretary David Lammy, comes as the UK signed a bilateral agreement.
Marles and Healey signed the treaty regarding nuclear submarines in Geelong, Australia.
Marles said: "In military terms, this represents the most significant leap in our (Australia's) military capability since the establishment of the Navy in 1913."
He was, however, not drawn on questions about which countries represented the biggest security threat in Australia's region.