As of today, that would be against U.S. law.
Late this afternoon, President Obama signed the National Defense Authorization Act for Fiscal Year 2016, which was approved by a veto-proof majority of the U.S. Congress.
Among the provisions in the bill is Section 1036, which states:
"No amounts authorized to be appropriated or otherwise made available for the Department of Defense for fiscal year 2016 may be used— (1) to close or abandon United States Naval Station, Guantanamo Bay, Cuba; (2) to relinquish control of Guantanamo Bay to the Republic of Cuba; or (3) to implement a material modification to the Treaty Between the United States of America and Cuba signed at Washington, D.C. on May 29, 1934 that constructively closes United States Naval Station, Guantanamo Bay."
Thus, sorry Raul, no Guantanamo for you.