P&O Cruises Australia is extending the cancellation of sailings until the end of July.
The current rolling pause will affect cruises scheduled from June 18 to July 30.
The Carnival Corporation brand is also cancelling voyages to Papua New Guinea and the Solomon Islands for the remainder of the year “given the uncertainty around borders”.
This also affects this year’s Cairns season where the ship Pacific Explorer was to be based for two months from October.
The line has not been operating for more than a year due to Covid-19 travel restrictions in Australia.
“Guests and travel agents will be contacted directly with solutions and alternative arrangements that will be tailored on a booking-by-booking basis,” the line said.
However, the Australian company said it remains positive about a pathway for the cruise industry’s return to service.
P&O Cruises Australia president Sture Myrmell said: “We are sorry that some of our guests will be unavoidably inconvenienced by these changes to the existing schedule at a time when we remain optimistic about returning to service as society keeps opening up.
“We are continuing our discussions with governments and health authorities to develop a framework for the staged resumption of cruising.
“As those discussions continue, today’s changes are necessary as we take a practical approach to the current environment and continue to look forward to better days ahead.”
The company said it had continued its fleet transformation so that it is ready to resume its leading role as Australia’s home-grown cruise line “even amid the challenges of the past year”.
Myrmell added: “This includes preparing for Pacific Encounter and Pacific Adventure to join the P&O fleet this year to offer a very special cruising experience when we are again able to sail.
“As always, we thank our guests for their patience and understanding in relation to these changes, and especially for their continued loyalty.”