Curfew in place for Tonga's capital tonight as Pacific nation braces for 'destructive' Cyclone Gita

New Zealand's Ministry of Foreign Affairs and Trade has issued an official advisory warning people not to travel to Tonga as Cyclone Gita barrels towards the island nation today.

The advisory warns the cyclone is expected to hit as a Category 4 storm, bringing destructive winds, heavy rainfall, dangerous storm surge and flooding to Tonga.

New Zealand's High Commission in the Tongan capital of Nuku'alofa will be closed for the next two days as the cyclone rolls in, with staff and other Kiwis on the island urged to evacuate or seek suitable shelter.

Kiwis in Tonga are also being urged to sign up to the Safe Travel register to let family and friends back home know they're safe during the potentially devastating storm.

Tonga Police have ordered a curfew be put in place from 9pm until 7am in the Nuku'alofa CBD to ensure the safety of residents.

1 NEWS Pacific Correspondent Barbara Dreaver is in Nuku'alofa reporting on the preparations being made ahead of the cyclone.

"In downtown Nuku'alofa people are starting to nail down their roofs and many have already started to board up.

1 NEWS reporter shows you how Tongans are readying for category 5 storm. Source: 1 NEWS

"People have sent their staff home now, getting their emergency supplies and making sure their families are safe with Cyclone Gita possibly hitting as a Category-5 later tonight," she says.

Acting Prime Minister Semisi Sika today signed the state of emergency declaration due to "the destructive force winds and sea rises caused by Tropical Cyclone Gita".

"It is necessary for emergency powers to be exercised in order to prevent or minimise the loss of human life, illness or injury, property loss or damage, and damage to the environment," the declaration read.

Cyclone Gita is currently a Category 4 but could become a Category 5 when it hits Tonga about 7pm tonight.

Ofa Fa'anunu from the Tonga Meteorological service says Gita will be the strongest cyclone on record to hit the Kingdom.

He is warning the public to go to evacuation centres as soon as possible.

TVNZ weather presenter Dan Corbett with the latest update. Source: 1 NEWS