The United Nations is concerned that a U.S. decision to give border guards more authority to expel immigrants could prevent or discourage deserving refugees from obtaining political asylum, a U.N. official said on Friday. The policy change, announced on Tuesday, expanded the authority of border guards working for the U.S. Department of Homeland Security to order the immediate deportation of immigrants seeking asylum if they concluded they did not qualify, rather than send their cases to an immigration court. "We want to ensure and guarantee that a potential asylum seeker or refugee will have access to a fair proceeding so they will be protected if they meet valid criteria for being a refugee and deserving protection by a country," said Joung-ah Ghedini, spokeswoman for the U.S. regional office of the U.N. refugee agency UNHCR. The Homeland Security Department had no immediate comment. Border guards have the power to order an immigrant's immediate deportation as part of a federal procedure known as "expedited removal." The process, first used in 1996 when U.S. borders were policed by another U.S. agency, initially applied only to guards dealing with immigrants arriving either by sea -- mostly Haitians fleeing their homeland -- or at a U.S. airport. --more 2205 Local Time 1905 GMT