CARTAGENA, Colombia — President Barack Obama said Sunday he will be “angry” if an internal investigation shows Secret Service personnel engaged in misconduct while in Colombia because he expects representatives of the United States to act with the “utmost in dignity and probity” when traveling abroad.

But as he finished a weekend meeting with other Western Hemisphere leaders here, Obama said he would wait until the investigation concludes before passing judgment on the agents and military officers, part of a team he said performs “extraordinary work on a day-to-day basis protecting me, my family and U.S. officials.”

The official Summit of the Americas touched on hot topics such as drug policy and the exclusion of Cuba from the get-together, but informal conversation dwelled on the Secret Service scandal.

Eleven agents were ordered back to the United States and placed on administrative leave for misconduct, and five U.S. military personnel were confined to quarters for violating curfew, after local police were called to the Hotel Caribe early Thursday. U.S. officials said women believed to be prostitutes were in some of the Americans’ rooms.

The Secret Service and the Department of Defense are both looking into the allegations.

The Secret Service personnel were not part of the Presidential Protection Division, the elite unit assigned to Obama, but provide security to U.S. government functions, buildings and officials.

“We’re representing the United States … when we travel to other countries,” Obama said in Cartegena. He wants members of the U.S. delegation to hew to “the highest standards” because “we’re here on behalf of our people.”

Earlier, in Washington, Rep. Darrell Issa, R-Calif., said he would conduct “an over-the-shoulder investigation” of the embarrassing episode. Issa, who chairs the House Committee on Oversight and Government Reform, told CBS’ “Face the Nation” that it was too soon to say if he would call hearings.

“This kind of a breach is a breach in the federal workforce’s most elite protective unit, and they don’t just protect the president, of course — they protect the Cabinet members, the vice president, the first family, candidates,” Issa said. “So when you look at this, you realize if you can have this kind of breakdown, one that could lead to blackmail. … We’ve got to ask, where are the systems in place to prevent this in the future?”