The supreme court has given the Trump administration a green light to turn back asylum seekers at the US-Mexico border, in a decision that fundamentally reshapes the US asylum system.

The Trump administration has sought for years to block migrants from setting foot on US soil, where federal law guarantees them the right to claim asylum and protection from persecution. The ruling will allow that practice to resume, concluding a battle that has spanned three administrations.

The vote was 6-3, with justices Samuel Alito, John Roberts, Clarence Thomas, Neil Gorsuch, Brett Kavanaugh and Amy Coney Barrett concurring. Justices Elena Kagan, Ketanji Brown Jackson, and Sonia Sotomayor all dissented, with the latter penning a biting 35-page long dissent – notably almost twice as long as the Alito majority opinion.