In the an interview with The Weekend Australian, the director general of the Australian Security and Intelligence Organisation (ASIO) says while the terrorism threat has "plateaued", it was still at an unacceptably high level and had to be brought down.

Mr Lewis warned the espionage threat shows no sign of abating with attempted foreign interference, including cyber-attacks and tradition spy craft, as well as unwelcome influence within Australia's political system.

"It is an unprecedented level of activity ... it's not visible to most people," he told the newspaper on Saturday, although added this was not peculiar to Australia.

Mr Lewis also says security agencies endure a game of "cat and mouse" with ever changing technological developments

"It's constant. Every day there is a discovery. Some of them are more alarming than others," he says.

Mr Lewis, who will step down from his position in September after five years, says while the benefits of globalisation are undeniable, it has also presented heightened security challenges.

"A lot of this is in the criminal field, which is not our business," he says.

"Where it is state-based threat to the country then that is ASIO's business and we are addressing that on a daily basis."

Similarly, he says while improving technology is overwhelmingly good for the community, technological developments are happening "every five minutes"and that poses a downside risk to it.

"It is true now that a person who would wish us ill is far more empowered as a result of the technology at their disposal than once upon a time," he said.

"In this sort of environment ... you need friends and one of the great features of ASIO is our very strong relationship in the Five Eyes community and beyond, where we have like-minded travellers in the world who need to increasingly work together to maintain security."

The Five Eyes intelligence alliance comprises Australia, Canada, New Zealand, the UK and US.

Australian Associated Press