Following the Supreme Court ruling, the reformed travel ban can take effect as soon as Thursday.
For everybody else, though, Mr Trump's travel ban may take effect.
Those affected are people attempting to travel to the States from Iran, Libya, Somalia, Sudan, Syria and Yemen.
The court said that Trump's executive order distinguished between foreigners who have "some connection to this country" and those who do not, and said the government had committed to review cases for those with some connection to the United States on a case-by-case basis.
But the other six kept blocking it as it applies to those traveling to the US on employment, student or family immigrant visas as well as other cases where the traveler can show a "bona fide" connection to the U.S.
While on the White House's South Lawn Monday, President Trump said he feels "very good" about the Supreme Court's decision.More news: A weakening Cindy leaves behind tornado damage in Alabama
On Monday, Trump stated, "As president, I can not allow people into our country who want to do us harm".
Even without the ban in place, arrivals from the six countries has dropped sharply, in part due to the "extreme vetting" approach of United States authorities, toughening their scrutiny of visa applicants.
"I want people who can love the United States and all of its citizens, and who will be hardworking and productive". The legal and political battle over the president's travel restrictions-beginning with his ill-fated order on January 27th and continuing with the revised policy on March 6th-has raged for five months. He said in a statement that his "number one responsibility" is to keep the American people safe.
Trump said today's ruling was vindication of his approach and allowed him "to use an important tool for protecting our nation's homeland". Monday's order appeared focused on balancing the parties' interests, with its argument that Americans aren't sufficiently "burdened" if they have no connection to the foreign national seeking entry, and the foreign nationals themselves don't have a right to come in. Will the travel ban even still be an issue by the time the justices hear arguments? But critics have called the order a mean-spirited, intolerant and un-American "Muslim ban".
Justice Clarence Thomas, joined by Justices Samuel Alito and Neil Gorsuch, wrote separately to say they would have revived Mr Trump's travel ban in full. (Read: someone trying to pick a fight.) In this way, it might seem to uphold the lower courts' sympathy to the plight of immigrants, and their doubts as to the ban's substantive legality. USA Today said that it is unclear whether or not the decision was truly unanimous because the court issued a "per curiam" opinion that no one signed.
Trump had suffered a series of defeats in lower courts over the ban, with two federal appeals courts maintaining injunctions on it by arguing that his executive order discriminated against travelers based on their nationality.
The Trump administration said the ban was needed to allow an internal review of the screening procedures for visa applicants from those countries. In response to the criticism, the administration revised the ban, but opponents said that it was still discriminatory towards Muslims. Writing for the 10-3 majority, Chief Judge Roger Gregory said the executive order "speaks with vague words of national security but in context drips with religious intolerance". And in reaching its ruling, the Supreme Court went out of its way not to say what was likely to happen.