Australia is closely monitoring a Chinese navy task group in the country's exclusive economic zone off its east coast but the ships did not pose any threats as they had not breached any maritime laws, Defence Minister Richard Marles said on Thursday.
A People's Liberation Army Navy frigate, cruiser and replenishment vessel had last week entered Australia's maritime approaches with the frigate transiting the Torres Strait between Australia and Papua New Guinea.
It has since moved south, sailing within 150 nautical miles (240 km) of the coast of Sydney, the Financial Times reported. A defence department statement did not mention the location.
"We are keeping a close watch on them and we will be making sure that we watch every move," Marles told Sky News.
"And whenever this mission is over on the part of the Chinese task group, we will assess everything we have seen to make a proper assessment of exactly what they were trying to achieve through this mission."
Australia's air force and navy were monitoring the ships, he said.
"This is not unprecedented but an unusual event. Just as they have a right to be in international waters ... we have a right to be prudent and to make sure that we are surveilling them, which is what we are doing," Marles said.
The sailing of the Chinese ships comes after Australia this month raised concerns with Beijing over what it said were "unsafe and unprofessional" actions by a Chinese fighter jet towards an Australian maritime patrol in the South China Sea, an account disputed by Beijing.
China has been looking to increase its influence in the Pacific, which for decades Australia and the United States have seen as their sphere of influence and are seeking to deter the Pacific island nations from forming security ties with China.
Marles is expected to meet on Thursday with his Papua New Guinean counterpart, Billy Joseph, as both countries look to enter into talks on a bilateral defence treaty.
