President Barack Obama’s top counterterrorism adviser said Thursday that the administration had not abandoned its pledge to close down Guantanamo Bay and announced that no new prisoners would be sent to the controversial detention facility.

"We’re not going to bring people to Guantanamo," Deputy National Security Adviser John Brennan told reporters, according to Politico. "It’s this administration’s policy to close Guantanamo and, despite some congressional hurdles that have been put in our path, we’re going to continue to pursue that."

Obama halted military commissions in January 2009 and called for some terrorism suspects to face trial in federal civilian courts, but Congress blocked the transfer of Guantanamo detainees to the United States.

In March 2011, Obama issued an executive order that allowed military trials for terror suspects at Guantanamo Bay to resume, a move that was condemned by human rights organizations. The order also required compliance with the Geneva Conventions.

Brennan said Thursday that any captured terrorism suspect would face civilian criminal prosecution. If that was not feasible, the suspect could be brought to the United States to face trial by a military commission.

"I certainly have not heard anybody exclude inside the U.S. for such a commission proceeding," he added.

The announcement comes after Sen. John McCain (R-AZ) added a provision to the National Defense Authorization Act requiring all captured terrorism suspects to be immediately placed in military custody.

"I am concerned about efforts in Congress to limit our ability to handle individual cases," Brennan said. "By limiting our flexibility, they make it more difficult for us to do our job."

Many Republicans were outraged in July, after learning that an accused Somali militant, Ahmed Warsame, was transferred to FBI custody, read his Miranda rights, and would face trial in New York.

On Thursday, the Obama administration also threatened to veto the renewal of the Intelligence Authorization Act unless changes were made to protect diplomatic communications regarding the transfer of Guantanamo detainees.

They said requiring the State Department to share that information with Congress could "have a significant adverse impact on the willingness of foreign partners, who often expressly request this information not be disseminated, to communicate frankly on these matters."