The United Nations refugee agency UNHCR said on Friday that its legal experts were reviewing a new U.S. policy to sharply limit migrant asylum claims, but declined to comment further, Reuters reported.

“The policy is being reviewed by legal colleagues. I understand it is a lengthy document. It needs to be carefully reviewed,” UNHCR spokesman Babar Baloch told a news briefing, in response to a reporter’s question about whether it would violate U.S. commitments under international refugee law.

The Trump administration unveiled new rules on Thursday to sharply limit migrant asylum claims by barring individuals who cross the U.S. southern border illegally from seeking asylum.