The Supreme Court on Monday allowed the Trump administration to enforce its 90-day ban on travelers from six mostly Muslim countries, overturning lower court orders that blocked it.
The action is a huge victory for President Trump in the biggest legal controversy of his nascent presidency.
As a result of the decision, people from Iran, Libya, Somalia, Sudan, Syria and Yemen who do not have a legal relationship with a person, school, business or other entity in the US would be barred from entry.
Trump said last week that the ban would take effect 72 hours after it was cleared by courts.