Tourism in North Korea is tightly controlled by the North Korean government. All tourism is organized by one of several state-owned tourism bureaus, including Korea International Travel Company (KITC), Korean International Sports Travel Company (KISTC), Korean International Taekwondo Tourism Company (KITTC) and Korean International Youth Travel Company (KIYTC). The majority of tourists are Chinese nationals: one 2019 estimate indicated that up to 120,000 Chinese tourists had visited North Korea in the previous year, compared to fewer than 5,000 from Western countries. In response to the threats posed by the COVID-19 pandemic in North Korea, North Korea closed its borders to foreign tourists on 22 January 2020. As of 8 April 2021, tourism has not been allowed to resume and the economic losses are estimated to be at least $175 million. Restrictions and warnings Interactions between foreign tourists and local people have historically been tightly controlled. , foreigners can buy SIM cards at Pyongyang airport, providing access to international calling. The Swedish diplomatic mission to North Korea emphasises that contempt for the North Korean nation, its leaders and its symbols such as its national flag, portraits of their leaders, propaganda posters, etc. are regarded by North Korean authorities as very offensive. The tolerance level for disruptive behaviour is minimal and this can lead to long term imprisonment or hard labour. On 1 February 2017, the United States released a travel warning to United States citizens, warning would-be visitors of previous encounters and dangers in North Korea. Since 1 September 2017, the United States Department of State has prohibited the use of U.S. passports (except those with a special validation) for travel to North Korea, arguing that U.S. citizens have been subject to arrest and long detention for actions that would not otherwise be a cause for arrest in the United States or other countries. The U.S. Department of State also states that it has received reports of North Korean authorities detaining U.S. citizens without charges and not allowing them to depart the country. North Korea has detained U.S. citizens who were part of organized tours. Guided tours Guided tours for tourists are mandatory. , North Korea has been open to tourists during the winter. The Masikryong Ski Resort outside Wonsan City in Kangwon Province opened in early 2014. While tourists have historically been restricted to Pyongyang, some tours have recently been able to expand to other parts of the country such