Most countries require a visa, which costs US$50 for most nationalities (US$100 for citizens of the USA) for a single-entry visa valid for up to three months. Officially, all travellers who come from a country with Tanzania diplomatic representation must obtain visas in advance. One-month single-entry visas are also currently issued on arrival at both Dar es Salaam and Kilimanjaro International Airports, at the Namanga border post between Tanzania and Kenya, and at Tunduma border.