When President Donald Trump's administration announced last week that it would require green card seekers to apply from their home countries instead of in the U.S., immigration attorney Flavia Santos Lloyd's phone began ringing off the hook with clients worried about the implications for them.

Lloyd wasn't sure what to tell them, but she knew the confusing new policy would slow down applications."It has a chilling effect because we have some cases that we were going to proceed and I can tell already, we should wait and see what's going on," she said.U.S. Citizenship and Immigration Services announced Friday that foreigners in the U.S. who want a green card will need to leave and apply in their home country, barring some unspecified exceptions.The announcement, which potentially affects hundreds of thousands of green card applicants a year, was the latest immigration policy unveiled by Trump's Republican administration to stun and confound lawyers, advocates and immigrants. It's also part of a pivot by the administration to target legal pathways to immigration, after focusing since last year mostly on migrants in the U.S. illegally."This is simply an attempt to try to limit and scare people away from the legal immigration process," immigration attorney Charles Kuck said, adding that he expected legal action against the change. "This is a scare tactic."As worried immigrants and their employers flood immigration law offices with questions, it's unclear what the effect will be, what exceptions might be allowed and how the policy will play out on the ground.Some green card seekers were already facing questions about why they should be allowed to apply from the U.S.A confusing rollout for the new policyFor more than half a century, foreign nationals with legal status have been able to apply for and complete the process for permanent residence in the United States — including people married to U.S. citizens, holders of work and student visas, and refugees and political asylum-seekers, among others.That appeared to change suddenly on Friday, when USCIS announced the shift on its website."From now on, an alien who is in the U.S. temporarily and wants a Green Card must return to their home country to apply, except in extraordinary circumstances," the agency said.