A U.S. Embassy spokesman says consular officials met with a 14-year-old boy accused of being a drug cartel assassin but that his citizenship has not been determined.
Spokesman Alexander Featherstone says officials visited the boy Monday to provide him with information on a local attorney and to monitor his welfare.
Featherstone said Tuesday that the embassy has not confirmed his citizenship but that he was offered consular assistance "in case he is a U.S. citizen."
Mexican officials and the boy's family say he was born in the United States.
Meanwhile, federal prosecutors say they are detaining two of the boy's sisters for 30 days for investigation of possible kidnapping charges. The women are aged 19 and 23.