The local developer says it will be more than 1 kilometre high and will be the centrepiece of a AED140bn ($38bn) development known as Nakheel Harbour & Tower.
"The cost of construction of the tower, canal and other buildings will be AED140bn," says Sultan Ahmed bin Sulayem, chairman of Dubai World.
Photo gallery: Nakheel Harbour & Tower development
In June, sources close to the project said the tower had been designed to be 1.4km tall.
The development will be on the proposed Arabian Canal next to Ibn Battuta mall and Jumeirah islands. It will cover an area of 2.7km and will be home to more than 55,000 people.
The main tower will be surrounded by 40 smaller towers, ranging from 20 to 90 floors.
The tower will be taller than the Burj Dubai, which is expected to be about 815 metres when completed.