BOGOTA, Colombia — At a meeting last August in the Oval Office to discuss sanctions on Venezuela was concluding, President Trump turned to his top aides and asked an unsettling question: With a fast unraveling Venezuela threatening regional security, why can’t the U.S. just simply invade the troubled country?

The suggestion stunned those present at the meeting, including Secretary of State Rex Tillerson and national security adviser H.R. McMaster, both of whom have since left the administration. This account of the previously undisclosed conversation comes from a senior administration official familiar with what was said.