Broward County in the US state of Florida has signed a 15-year agreement with Carnival Corporation to upgrade Port Everglades at a cost of $34m.
Under the agreement the cruise operator will allow 1.7 million passengers to travel through the port every year, accounting for nearly 25.5 million travellers during the next 15 years.
Port officials estimate Carnival's agreement will create $500m in revenue.
The port will spruce up four existing cruise terminals, build new elevators and work on escalators and loading bridges.
Upgrades at the port will cost the county about $30m and the architectural and engineering work will cost about $4m.
Carnival has also agreed to gradually increase its guarantee of minimum passenger movements by 60%.