Published: Aug 05, 2011 7:52 PM EDT

HAVANA (AP) - An American man who has been behind bars in Cuba for more than a year and a half has exhausted all of his legal options in Cuba.
Alan Gross, his family and U.S. officials can now only hope for a release on humanitarian grounds.
Cuba's highest court today upheld his 15-year prison sentence for crimes against the state. It's a case that has further strained relations between Washington and Havana.
Gross was found guilty of bringing satellite and other communication equipment into Cuba illegally. He has acknowledged that he was working on a democracy program funded by the U.S. Agency for International Development. But he says he meant no harm to Cuba's government and was only trying to help the island's tiny Jewish community.
His lawyer in the United States says today's ruling isn't a surprise, but it's still disappointing. He says family members are still hoping there can be a "diplomatic resolution" of the case.
Cuban officials have said privately that they are sympathetic to humanitarian appeals, but that they wouldn't consider them until after the ruling from Cuba's Supreme Court.

(Copyright 2011 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)