Employees who work abroad may be sent to the United States for consultations, orientation, QA, QC, etc. B-1 foreign nationals can perform certain types of services for an employer in the United States, but cannot be paid a salary in the United States; the salary should continue to be paid by the overseas employer. The period of admission is flexible (1 month to 6 months) depending upon the purpose of the visit and can be extended if necessary.