The Prime Minister has responded sceptically to recent peace overtures from North Korea, warning it could be an act of deliberate deception by Pyongyang.
North and South Korea have announced that their teams will march under a single flag at the Winter Olympics in the wake of recent peace talks.
But Malcolm Turnbull said the thaw in ties could be cosmetic.
“We obviously always welcome, in the field of sport, people coming together, but we have to be clear-eyed about this,” Mr Turnbull said.
“History teaches us a very bitter lesson. [North Korea] has a long habit of ratcheting up their militarisation, and then going into a lull, trying to persuade people they are changing their ways, changing nothing, and then ratcheting up again.
“I don’t think anyone imagines that North Korea participating in the Winter Olympics will lead to denuclearisation of the Korean Peninsula.”
Mr Turnbull made the comments while visiting a military base in Tokyo with Japanese Prime Minister Shinzo Abe.
Mr Turnbull inspected surface-to-air missile launchers at the base, and said it showed how Japan had to defend itself against the threat of an attack.
Both Australia and Japan have been pushing the global community to ratchet up economic sanctions on the North Korean regime to force it to abandon its nuclear weapons program.
“The signal to North Korea is one of absolute solidarity between Australia, Japan, the United States, China — and indeed the rest of the global community,” Mr Turnbull said.
“We have to maintain those sanctions. That is the only way we will achieve the bringing of this reckless regime back to its senses. Prime Minister Abe and I are absolutely of the same mind over that.”
Japan’s Foreign Minister has also warned that North Korea might be participating in talks in order to “buy time” for its nuclear weapons program.
Mr Turnbull and Mr Abe are also expected to discuss closer military cooperation and the Trans-Pacific Partnership (TPP) trade agreement.
The Trump administration dealt the TPP a huge blow last year when it pulled the US of the agreement.
The remaining 11 nations were on the verge of signing a new deal in November before Canada raised last-minute objections, angering several other countries and jeopardising the entire agreement.
But Mr Turnbull predicted that the revised TPP could be signed as soon as March when trade ministers meet in Chile.
“Prime Minister Abe and I are very committed to it. We’re using all of our persuasive skills, such as they are, to ensure we can get it agreed,” Mr Turnbull said.
“It is manifestly in Australia’s interests and in Japan’s interests.”