A dialect is generally considered as a variation of some other language. There is often the implied implication that a dialect is less prestigious than the language of which it is a dialect. A political definition says that a language is a dialect with an army behind it. Theoretically, if the government of Belize decided that Kriol would become the national language of Belize, then Kriol suddenly becomes a language. But nothing has changed with the way Kriol is spoken.
Some people feel that a language is a dialect with a body of literature.
Belize Kriol is beginning to have a few items written in Kriol. No one knows. Some people feel that a language is spoken by a large group of people multi-nationally, a dialect is only regional. By this definition Kriol would qualify as a language because there are speakers of Belize Kriol living in the United States and England, as well as Belize and elsewhere. There are also other varieties of Creole spoken in nearby countries, such as Nicaragua and Colombia, that are extremely similar to what is spoken in Belize.