Australia's defense forces, joined by New Zealand, have been monitoring Chinese navy vessels since they were spotted last week.

Defence ministry spokesperson Wu Qian on Sunday rejected Australia’s version of events surrounding the live-fire drills, which forced commercial flights to divert from trans-Tasman routes on Friday.

An international relations professor is warning China's activity in the Tasman Sea shows it wants to establish a permanent military presence in the Pacific, and New Zealand must prepare for that.