http://travel.state.gov/visa_services.html
看看這段話
Effective April 1, 2002, aliens who have applied for and been refused visa
issuance while outside the U.S. are prohibited from returning to the United
States, even if they are in possession of a valid I-94 form. The revised
regulation also prohibits aliens who are citizens of countries on the State
Department's list of State Sponsors of Terrorism from re-entering the U.S.
using solely an I-94 form if their visa has expired 。
就是說如果簽證沒有被拒,而我們又不是State sponsors of terrorism的公民,就可以
享受Automatic Re-entry With Valid Form I-94。也就是說可以從canada或mexico回來
是合法的。
但是問題是一旦被check,I94會不會收走,還有回到美國境內後合法的逗留期限是多久