A full emergency has been declared at Christchurch International Airport for an incoming flight this afternoon.

Fire & Emergency NZ, ambulance, and airport staff are on standby for the flight.

It’s understood to involve Fiji Airways flight FJI450, taking off from Christchurch and headed for Nadi.

It is currently the most tracked flight in the world on Flightradar24.

The issue happened after take-off from Christchurch airport and the Fiji Airways plane is circling the city. Image / Flightradar24

The plane is currently circling over Canterbury, around the Lake Ellesmere area.

A Fire & Emergency NZ spokesperson said four appliances and a command unit are standing by, waiting for it to land.

Christchurch International Airport is under full emergency for an incoming flight which had issues after take-off. Photo / George Heard

An airport spokesperson confirmed the plane had taken off from Christchurch International Airport but will be "returning for an unknown reason, so it is circulating".

Police say they were notified of “an incident at Christchurch Airport” at around 2.30pm and are also in attendance.

MORE TO COME.