Secretary of State John Kerry said Monday there is no "specific threat" against the United States from the Islamic State ahead of the busy Thanksgiving holiday.
Security within the country has become a top issue in the wake of the terrorist attacks in Paris 10 days ago, as the Islamic State has said it would carry out similar attacks in other world capitals, including Washington, D.C.
Over the weekend, authorities in Belgium launched a series of strikes in an effort to stop what they deemed to be an imminent threat of an attack there. That situation prompted the U.S. embassy in Brussels to declare a Level 4 threat level, which is a "serious threat of imminent attack."
Belgium closed all its schools and train stations Monday, and police were conducting searches throughout Brussels.