Slavery has been called "deeply rooted" in the structure of the northwestern African country of Mauritania, and "closely tied" to the ethnic composition of the country. In 1905, an end of slavery in Mauritania was declared by the colonial French administration but the size of Mauritania prevented enforcement. In 1981, Mauritania became the last country in the world to abolish slavery, when a presidential decree abolished the practice. However, no criminal laws were passed to enforce the ban. In 2007, "under international pressure", the government passed a law allowing slaveholders to be prosecuted.