Spy devices found in gifts given to ADF by foreign military

Revealing declassified details of a foiled spy plot during his annual threat assessment on Tuesday evening, Mr Burgess warned espionage and foreign interference had reached "extreme levels" over the past five years which has escalated since the establishment of the AUKUS alliance.

"Multiple countries are relentlessly seeking information about our military capabilities. Defence personnel are being targeted in person and online," Mr Burgess said.

"Some were recently given gifts by international counterparts. The presents contained concealed surveillance devices.

"AUKUS will remain a priority target for intelligence collection, including by countries we consider friendly."

Mr Burgess did not name the country responsible, nor did he reveal which defence cohort was targeted, but said foreign entities will seek to undermine confidence among military allies and diminish public support for AUKUS if regional tensions escalate.

During his speech, the director-general of the nation's peak spy agency also revealed investigations had identified at least three different countries "plotting to physically harm people living in Australia".

He spoke of an operation in which an Australian human rights activist was tricked into visiting a developing country by a foreign intelligence service who had arranged for the person to be injured or killed in an "accident". The plot was foiled, and the person was unharmed.

"More recently - last year in fact - ASIO intelligence indicated a different hostile foreign intelligence service wanted to harm and possibly kill one or more individuals on Australian soil," Mr Burgess said.

"Working with our international partners, we determined this plot was part of a broader effort by the regime to eliminate critics of the foreign government around the world - activists, journalists, ordinary citizens."

In August last year, Mr Burgess raised the national terrorism threat level to the second-highest level - "possible" - for the first time in a decade.

He said the war in Gaza has not yet directly inspired terrorism in Australia but has undermined social cohesion and triggered protests, in turn making instances of politically motivated violence more likely.

Mr Burgess said the agency had no plans to lower the threat level for the foreseeable future and anticipated an increase in security incidents during the second half of the 2020s.

"The result of all this will be a dynamic security environment with an unprecedented number of challenges and an unprecedented cumulative level of potential harm," he said.

"Australia has never faced so many different threats at scale at once."

Defence Minister Richard Marles said a "number of countries" were interested in Australia's increased spending on defence and national capabilities.

"We live in a very complex and in many respects threatening environment, and we need to be making sure that we are prepared for that," Mr Marles told Nine's Today.

The opposition spokesman for home affairs, James Paterson, said there was a "pretty clear short list" of the states interested in Australia's activities in the region.

"It is the authoritarian states and those who have interests in our region. I'm not going to name them explicitly," Mr Paterson said.