A U.S. Coast Guard cutter crossing the Tasman Sea as part of maritime security cooperation with Australia and New Zealand knew Chinese naval ships were in the area but had no interaction with them, its commanding officer said on Tuesday.

A Virgin Australia pilot alerted Australian authorities about a live-fire drill by Chinese naval ships last week in the Tasman Sea that forced 49 flights to change their paths, Australia's air traffic control agency head told a parliamentary committee.

Chinese naval drills in international waters between Australia and New Zealand caused dozens of flight diversions.