US President Barack Obama promoted freedom of expression during an arranged meeting with young people in Ho Chi Minh City on Wednesday.
"You've got to let people express themselves," he told a female rapper who asked whether governments should play a role in promoting arts.
"That's part of what a modern 21st-century culture is all about."
The comments were among Obama's most direct, and personal, on the subject of human rights during his three-day visit to Vietnam.
"Governments sometimes get nervous about art," Obama said. "But if you try to suppress the arts, then I think you're suppressing the deepest dreams and aspirations of a people."
Around 800 people attended Wednesday's event, most from the Young Southeast Asian Leaders Initiative, a US programme launched by Obama in 2013 on leadership exchanges for 18-to-35-year-olds.
The event was held in Vietnam's vibrant southern commercial hub of Ho Chi Minh City.