GUANTANAMO BAY NAVAL BASE, Cuba — A new dining hall for guards at the Guantanamo Bay detention center has a shimmering view of the Caribbean and a lifespan of 20 years.

Barracks scheduled to start getting built next year are meant to last five decades.

And the Pentagon has asked Congress to approve money for a new super-max prison unit to be designed with the understanding that prisoners will likely grow old and frail in custody — some perhaps still without being convicted of a crime.

President Donald Trump’s order in January to keep the Guantanamo jail open, and allow the Pentagon to bring new prisoners there, is prompting military officials to consider a future for the controversial facility that the Obama administration sought to close.

Officials talked about the plans in a frank manner as a group of journalists toured the isolated base where 40 men are still held behind tall fences and coils of razor wire on the southeastern coast of Cuba.

“We’ve got to plan for the long term,” Army Col. Stephen Gabavics, commander of the guard force, told reporters recently. “We ultimately have to plan for whether or not they are going to be here for the rest of their lives.”

The Pentagon was investing in upgrades at the Navy base under President Barack Obama, whose push to shutter the detention center couldn’t overcome opposition in Congress. But those projects, including the $150 million barracks, were funded with the understanding that they could be used by the personnel of the Navy base that hosts the detention center.

Now they are viewed as part of a broader effort to be able to operate the prison for many years to come.

“Now my mission is enduring,” said Adm. John Ring, commander of the task force that runs the jail. “So I have all sorts of structures that I have been neglecting or just getting by with that now I’ve got to replace.”

The Pentagon wants at least $69 million to replace Camp 7, the super-max unit that holds 15 men designated as “high-value detainees” who were previously in CIA custody. They include five men facing trial by military commission at Guantanamo for planning and aiding the Sept. 11, 2001, terrorist attack.

Officials say Camp 7 is in need of major repairs, with cracking walls and a sinking foundation.

The new unit, which would be known as Camp 8, would have cell doors wide enough for wheelchairs and hospice beds and communal areas so elderly prisoners could help each other as they grow old.

The White House has endorsed the proposal, but it is not known whether Congress will approve it.

“We have the responsibility for the detainees that we have here, regardless of what the political flavor is outside there,” Gabavics said.