AIR New Zealand has cancelled all flights in and out of New Zealand’s capital Wellington, as the remnants of tropical cyclone Gita pummelled the country.

The national carrier said all flights to the capital would be grounded from 2.45pm local time as weather authorities issued warnings of severe weather and heavy rain and gusts of up to 150km/h.

Air New Zealand’s flights will be grounded in and out of the capital Wellington through to midnight Tuesday.

Prime Minister Jacinda Ardern told reporters at Parliament that the military had been deployed to areas likely to be worst hit and the country’s national Civil Defence office in Wellington was on standby to help local authorities.

“My message still to people is please look out for your local warnings and expect disruption to travel and please just be careful,” she said.

Cyclone Gita hit the Pacific island nations of Fiji and Tonga last week, packing winds up to 171km/h and causing widespread destruction and flooding.

It had earlier caused extensive damage in Samoa and American Samoa.

The cyclone had since been downgraded to a storm, but forecasters warned it was still likely to wreak havoc as it traversed the centre of New Zealand, parts of which were still reeling from a huge storm that prompted authorities to declare of states of emergency at the start of February.

More than 40 schools and preschools were closed in the upper South Island, while local mayors urged people not to leave their homes.

Wellington Roads have also been closed after Gita left a trail of destruction in Tonga, Samoa and Fiji.

The storm is expected to slam into central New Zealand late Tuesday and early Wednesday, according to a MetService statement.

Transport authorities shut a stretch of highway along the east coast of the South Island and the Department of Conservation was closing picturesque seaside hiking tracks and campsites along the West Coast and ushering tourists away from low-lying areas, media said.

Popular tourist train service TranzAlpine service was also cancelled for Tuesday and Wednesday.

Heavy rain would cause slips, streams and rivers to rapidly rise and flooding, MetService said. There was also the risk of coastal inundation overnight on Tuesday due to the combination of tides and large waves in excess of six metres.