The least-friendly countries for US tourists include a number of countries that have hostile relations with the United States, or have ongoing military conflicts within their borders.

Governments frequently arrest and imprison American tourists:
 - Iran
 - North Korea
 - Russia

Ongoing warfare or government collapse:
 - Libya
 - Ukraine
 - Somalia
 - Haiti
 - Syria

For US tourists, it is worth checking the United States Department of State's Bureau of Consular Affairs, the government bureau that creates and updates travel advisories, for the most recent news on a country before traveling there.
spam fails_task lang_mismatch pii not_appropriate hate_speech sexual_content quality toxicity humor helpfulness creativity violence