US commanders at the base considered such long term investment in infrastructure as an indication that the US administration intends to continue operating the detention center.
"It only makes sense to do if we're going to be here for any period of time," the Miami Herald quoted Navy Capt. Kirk Hibbert as saying.
The project needs congressional approval and is expected to be part of the budget for the fiscal year 2013.
The fiber optic cable will run 800 miles (1,290 km) from Guantanamo Bay prison to South Florida. The project, which could start operating within two years, would improve telecom access for American military personnel in Cuba.
When President Barack Obama was campaigning to win office, he promised to close the Guantanamo Bay prison camp. However, his administration is now preparing to spend tens of millions into modernizing the base.
Obama also signed an executive order in 2009 to close the notorious facility, but his order was delayed, and later issued an executive order in 2011, allowing the indefinite detention of Guantanamo prisoners.
There are 169 detainees in the prison, with majority of them not having a chance to stand trial. About half of them have been cleared for release, but they have no prospects of being freed following a ban on transfers from Guantanamo.
The US is accused of using torture techniques, including simulated drowning, known as water-boarding, on the detainees, many of whom have been held without charge for ten years.
The US military has planned to install a $40 million fiber optic cable between the Guantanamo Bay prison in Cuba and the US mainland, indicating the US government will continue holding the notorious facility.
The project is aimed at bringing “the infrastructure of the naval base up to par with other government agencies,” said Army Lt. Col. Todd Breasseale, a spokesman for the Guantanamo military commissions.