Third Country Nationals who neither work nor have permanent residence status in Denmark should be aware that it is very difficult to qualify for a nonimmigrant visa because it is hard for them to demonstrate their permanent ties to their home countries
In such cases, the applicants should consider submitting their applications in their home countries or at a U.S. embassy or consulate with the routine responsibility for processing applications from the applicant's home country.
Effective January 12th. 2009, all individuals traveling on the VWP will be required to obtain an Electronic System Travel Authorization (ESTA) prior to traveling to the United States