WELLINGTON (REUTERS, XINHUA) - Air New Zealand warned on Monday (Feb 19) flights in and out of New Zealand faced major disruptions this week due to Cyclone Gita, set to hit the country on Tuesday, and encouraged passengers to defer travelling.

"We are anticipating significant disruption to our domestic network as well as some international services over the coming week," the airline said in a travel alert on its website.

Air New Zealand said it would not reimburse passengers for any costs or penalties like hotels and meals if flight schedules were disrupted.

"Any customer who chooses to commence their journey as planned must be advised that they do so at their own risk," the airline said.

Prime Minister Jacinda Ardern said the government was keeping a close eye on the cyclone and urged people to take local civil defence warnings seriously.

New Zealand's MetService issued severe weather warnings for most of the country's South Island, expected to be hit by heavy rain and gale-force winds, while it said western areas of the North Island will face strong northerly winds.

Singapore Airlines - which flies daily to Auckland and Christchurch, and four times weekly to Wellington via Canberra - said on Monday it was "closely monitoring the situation in Christchurch".

"As of now, all Singapore Airlines flights to and from New Zealand are continuing to operate as scheduled," the airline added. It advised customers to check its website regularly for updates.

Cyclone Gita hit the Pacific island nations of Fiji and Tonga last week, packing winds up to 275km per hour and causing widespread destruction and flooding. It earlier caused extensive damage in Samoa and American Samoa.

Authorities along the country's remote West Coast were meeting on Monday evening to decide whether to declare a state of emergency for the region, parts of which were still reeling from a huge storm that hit at the start of February.

Meanwhile, Australian authorities warned of dangerous surf conditions on Monday as massive 4-metre waves continue to smash the east coast of the country.

There were more than 150 people in total being rescued over the weekend, including a busy period in Sunshine Coast where 19 people were pulled from the water in just 10 minutes when conditions dramatically turned.

Lifesavers also had to perform a daring helicopter rescue when a man in his 50s was winched to safety after being stuck in dangerous seas for more than two hours.

Despite the treacherous conditions, many local boardriders have failed to heed the warnings, seeing the monster swells as the “perfect time to go surfing.”

“It’s heaps of fun!” 16-year-old Queensland surfer Nathan Hawker told local media.

Additional reporting by Lim Min Zhang