Petition - Treaty Skilled Worker Visa TN Petition A Petition for Treaty Skilled Worker Visa (in the U.S., TN application) refers to the process of applying for a TN (Trade NAFTA) visa at the U.S.-Canada or U.S.-Mexico border. The TN visa is available to Canadian and Mexican citizens engaged in specific professional occupations. Applicants must meet the qualifications outlined in the NAFTA agreement and provide the necessary documentation to demonstrate eligibility. Upon approval, the TN visa allows individuals to work in the U.S. temporarily in qualifying professional roles