Tony Abbott has called for Australia to implement a missile defence system to guard against a possible attack by North Korea.
Mr Abbott's comments come after North Korea threatened to launch four intermediate-range missiles at the waters just off the US Pacific territory of Guam. The missiles would reportedly fly over Japan en route to their target.
Mr Abbott says Australia should consider installing new systems against the threat.
Experts suggested last month that North Korea could launch ICBMs that have the range to reach northern Australia.
"Of course, we should be able to defend ourselves if they have missiles that can reach Australia," Mr Abbott told Fairfax Media.
"We should be urgently investing in upgraded missile defences.
"We should upgrade the capability of the air warfare destroyers so they're not just able to track incoming missiles but shoot them down.
"And we should look at the sort of system the US is installing in South Korea."
The US has installed the Terminal High Altitude Area Defence or THAAD system in South Korea.
Foreign Affairs Minister Julie Bishop said on Wednesday that a North Korean ICBM capability posed "an unacceptable existential threat to our country".
However, she said Australia was not a major target and wouldn't necessarily be drawn into the conflict should matters escalate that far.
Earlier in the week US President Donald Trump said he would deal with Pyongyang's threats with "fire and fury", while North Korea said that "only absolute force can work on him".