GENEVA (Reuters) - The United States must make sure anyone fleeing violence or persecution can get protection “without obstruction”, the U.N. refugee agency UNHCR said on Friday, hours after U.S. President Donald Trump signed an order limiting asylum rights.

Trump’s proclamation will effectively suspend the granting of asylum to migrants who cross the U.S. border with Mexico illegally for up to 90 days. From Saturday, when it goes into effect, migrants will have to present themselves at U.S. ports of entry to qualify for asylum.

Many of the people on the move in Central America and Mexico today are fleeing “life-threatening violence or persecution” and require international protection, the U.N. High Commissioner for Refugees (UNHCR) said in a statement issued in Geneva.

“UNHCR expects all countries, including the United States, to make sure any person in need of refugee protection and humanitarian assistance is able to receive both promptly and without obstruction in accordance with the 1967 refugee Protocol to which the United States is a party,” the agency said, referring to a protocol to the 1951 Refugee Convention.

It added that “long-standing insufficient reception capacity at official U.S. southern border ports of entry” was causing significant delays in northern Mexico, forcing many desperate asylum-seekers to turn to smugglers and cross the border irregularly.

“National security and dignified reception of refugees and asylum-seekers are not mutually exclusive, but rather mutually reinforcing,” it said.