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

Airliners were over the Tasman Sea crossing between Australia and New Zealand when the Chinese navy warned they were flying over a secret live-fire exercise, Australian Defense Minister Richard Marles said on Friday.

On Friday morning, three planes from Sydney bound for the New Zealand cities of Christchurch and Queenstown were in the air when they were warned by a Chinese warship of a live-fire exercise.

Australia expressed concern to China on Friday over the short notice given by the Chinese navy that it would hold a live-fire exercise in international waters between Australia and New Zealand, forcing airlines to divert flights,

The Chinese naval exercises, in international waters off Australia’s eastern coast, while legal, have nonetheless sparked alarm in Australia and New Zealand.

Australia said Saturday it has not received a satisfactory explanation from Beijing after Chinese warships off its east coast broadcast a "disconcerting" live-fire warning that forced commercial flights to change course.

Australia's Foreign Minister Penny Wong says her government has warned international airlines flying between Australian airports and New Zealand to beware of Chinese warships conducting a live-fire ex

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

An unprecedented number of military assets have been deployed to monitor Chinese ships operating off the Australian coastline.