WASHINGTON (AP) — Foreigners in the U.S. who want a green card will need to leave and apply in their home country, the Trump administration announced Friday, in a surprise change to a longstanding policy that sowed confusion and concern among aid groups, immigration lawyers and immigrants.For over half a century, foreign nationals with legal status have been able to apply for and complete the entire process for permanent residence in the United States — including individuals married to U.S. citizens, holders of work and student visas, and refugees and political asylum seekers, among others.The announcement from U.S. Citizenship and Immigration Services is the latest step by the Trump administration making legal immigration more difficult for foreigners already in the U.S. and for those hoping to come here. The changes comes on top of steps the administration has already taken to restrict and limit entry for people from dozens of countries. In some cases, there are outright bans on travel from those countries, while people from others face pauses in visa processing. Experts and attorneys warned that forcing people from those countries to return home to apply for a green card would result in them being barred from coming back.