To visit to the U.S. temporarily
1. ESTA (Electronic System for Travel Authorization)
The first time you visit the United States it’s usually for short-term sightseeing, business trips or visiting relatives. In this instance, you do not have to go to an immigration lawyer for complicated document procedures because of the visa waiver program between South Korea and the United States. If you qualify through the ESTA program, you can stay up to 90 days in the US without a visa. It is easy to apply for ESTA online, but one thing to note is that ESTA is likely to reject you if you have previously been refused a visa or have a criminal record. If you leave the United States and return,
you are eligible for a new 90-day stay, but if you use ESTA too often, the chance that you will be denied entry by the Immigration Service is high.
2. B-1/B-2 visa
If your ESTA is rejected or you need to stay in the U.S. for more than 90 days, you will need to apply for a B-1 / B-2 visa. Generally, a B-1 visa is for people who visit to the U.S. for business, such as in consulting, science, education, professional conventions/ conferences, to settle a real estate contract, or to travel for contract negotiation. B-2 visa is for relaxation travel, including sightseeing, visiting friends and relatives, medical treatment, and social or service activities. Often, B-1 and B-2 visas are combined and issued as a single visa, usually as a 10-year visa that allows a six-month stay.
You should remember that if you enter the US via ESTA without a US Visitor's Visa of B-1 or B-2, you may not be eligible for a change of status to another visa, such as the F-1 visa for students or the E-2 visa for investors that allows you to reside in the U.S. for a longer period. If you are not eligible for a long-stay visa with Consular Processing through the US Embassy in Seoul, South-Korea, it is recommended that you obtain a visitor visa and change your residential status once you are safely in the United States. The important point is that if you change your status within 90 days of entry into the United States, you will automatically be refused on the grounds of assumption that your intention of entry was fraud and not for short-term travel or business meetings.