A prostitution scandal involving US security personnel in Colombia and an unprecedented regional push to end the isolation of Cuba threatened to eclipse President Barack Obama's charm offensive to Latin America.
In a major embarrassment for Washington at the Summit of the Americas attended by more than 30 heads of state, 11 US Secret Service agents were sent home and five military servicemen grounded over misconduct allegations in a hotel.
Prostitutes were taken to the hotel, according to a Colombian police source.
The widening controversy was overshadowing a host of weightier topics at the two-day summit that began on Saturday.
I had a breakfast meeting to discuss trade and drugs, but the only thing the other delegates wanted to talk about was the story of the agents and the hookers said a Latin American diplomat in the city of Cartagena.
Locals were upset about the bad publicity for their city, and the scandal was raising eyebrows around the region.
Obama's guards expelled in Colombia over prostitution - shame the gringos think that Latin America is a brothel and they act like it too, commented left-leaning Venezuelan political commentator Nicmer Evans via Twitter.
Obama's rapprochement with the region - already undermined by the titillating headlines from Cartagena - also faces a rare display of unity among in Latin America in allowing communist-run Cuba at the next summit.
Argentina's foreign minister said the final summit declaration was stalled over the issue of Cuba, with 32 nations supporting its inclusion in the next Summit of the Americas, but the United States vetoing that.