Prime Minister Scott Morrison is set to unveil a plan to build a new nuclear submarine base on Australia's east coast.

The $10 billion installations will support the new nuclear-powered fleet of submarines being acquired by Australia under the AUKUS defence pact.

The Federal Government has shortlisted Port Kembla and Newcastle in New South Wales and Brisbane in Queensland for the site of the new base.

The government shortlisted the three east coast sites after considering 19 options.

Mr. Morrison will announce the new naval base today in a speech to the Lowy Institute think tank.

He will say an increase in the country's defense footprint is required to meet the large increase in Australia's submarine force.

The new east coast base will not replace or relocate any existing naval bases.

Last year the Federal Government announced earlier it would acquire the technology to build eight nuclear submarines when Australia joined the AUKUS defence pact with the US and Britain.

Defense experts estimate the new fleet could cost up to $171 billion.

Australia's decision to acquire nuclear submarines under the AUKUS pact triggered a major diplomatic row with France after scrapping a $90 billion contract for diesel-powered subs with a French defence company.

The coalition has been pushing national security as a major election issue.

Today Mr. Morrison is expected to warn that Australia faces its most difficult and dangerous security environment in 80 years.