An unusual series of military exercises by Chinese warships in the sea between Australia and New Zealand has prompted reproval from leaders in both countries about the amount of warning given.

New Zealand raised fresh concerns Monday over nearby live-fire drills conducted by Chinese warships armed with “extremely capable” weapons, an unprecedented show of firepower last week that analysts say are part of Beijing’s ongoing plan to build a blue-water navy with global reach.

The Chinese warships off Australia's coast are carrying missiles with a range of about 1,000 kilometres, New Zealand's defence minister says, warning of an urgent need for her government to bolster defence spending.

Beijing is now under scrutiny for not warning Australia or New Zealand of drills being performed in the Tasman Sea. Defence Minister Judith Collins has said this country and Australia aren’t “particularly worried”.

New Zealand Defense Minister Judith Collins said Monday that a Chinese naval group conducting military exercises in the Tasman Sea was armed with "extremely capable."

Sailing in Australia’s exclusive economic zone, the three vessels were not breaking international law, but they were unusually far south on an undeclared mission.

The Australian and New Zealand militaries are monitoring three Chinese warships that are moving unusually far south along Australia’s east coast on an unknown mission

The vessels were sailing in the Tasman Sea, and their announced intent to perform exercises prompted a call for commercial flights to divert course.

China defence ministry spokesperson Wu Qian said on Sunday that Australian complaints over recent Chinese live-fire naval drills in international waters between Australia and New Zealand were "hyped up" and "inconsistent with the facts".