WASHINGTON (Reuters) - The leadership of the U.S. military is 'embarrassed' by allegations that soldiers supporting President Barack Obama's recent visit to Colombia violated curfew and may have been involved in 'inappropriate conduct.'

"We let the boss down," said General Martin Dempsey, chairman of the U.S. Joint Chiefs of Staff.

Speaking in a news conference, he said the substance of the Summit of the Americas had been overshadowed by allegations of misconduct by members of the Secret Service and military, which the Colombian police said involved prostitutes.

"No one is talking about what happened in Colombia other than this incident," Dempsey told reporters.

(Reporting By Missy Ryan; Editing by Sandra Maler)