PORTLAND — Maine has joined other states in asking Congress to fund anti-human trafficking measures.

Maine Attorney Janet Mills and attorney generals in 46 other states sent a letter asking Congress to fund a measure passed in 2000 designed to protect human trafficking victims and help prosecute people doing the trafficking.

The letter says human trafficking is tied as the second largest and is the fastest growing criminal industry in the world, generating roughly $32 billion each year. According to a study of Department of Justice human trafficking task force cases, 83 percent of sex trafficking victims identified in the United States were U.S. citizens.