In a statement, Acting Prime Minister Semisi Sika said due to destructive force winds and sea rises associated with the category four storm, it was necessary for emergency powers to be exercised in order to prevent or minimise loss of life or injury and damage to property and the environment.
Gita has brought destructive force winds and sea rises and is expected to be closest to Tongatapu by midnight tonight.
It is also expected to intensify into a category 5 cyclone with winds of over 200km an hours.
The declaration of the State of Emergency will expire at 10am (local time) on 12 March, 2018 unless terminated earlier by the Prime Minister.
The public is being urged to use the time that they have to ensure their safety and that of people around them especially elderly people, young children, pregnant and lactating mothers and the disabled.
There are designated evacuation centres in each village and the public is being urged to contact their town officer.
His Majesty’s Armed Forces, National Emergency Management Office and Ministry of Health staff are picking up rubbish along the urban areas and already designated rural areas to avoid flying debris that may cause harm during the cyclone.