South Korea's foreign ministry has formally raised concerns with Washington over new US immigration rules that cap international students' authorised stays at four years and limit foreign journalists on I visas to 240 days. Deputy Foreign Minister Park Jong-han met US State Department Under Secretary Jason Evans in Seoul on Tuesday, warning that the policies could cause "unfair infringement" of South Korean nationals' rights and harm bilateral people-to-people ties. The US Department of Homeland Security announced the restrictions last week, and Seoul is now pressing Washington to ensure the rules do not produce unintended harm to what officials describe as a cornerstone of the two allies' relationship.