While US elected officials have an obligation to protect the security of Americans, denying entry to desperate refugees will not make the country safer, the president and CEO of Catholic Relief Services has said.

Sean Callahan, head of CRS, said: "Welcoming those in need is part of America's DNA."

"CRS welcomes measures that will make our country safer, but shouldn't jeopardise the safety of those fleeing violence should not add appreciable delay nor entail unjust discrimination," he said in a statement.