United Nations (United States) (AFP) - Governments that crack down on migrants are only harming themselves, UN Secretary-General Antonio Guterres warned Thursday ahead of UN talks on a global response to migration boycotted by the United States. Guterres presented a report to the General Assembly on ways to address the plight of the 258 million international migrants, some of whom are trapped in legal limbo. "Authorities that erect major obstacles to migration - or place severe restrictions on migrants' work opportunities - inflict needless economic self-harm," Guterres said. "They impose barriers to having their labor needs met in an orderly,...