Prime Minister John Howard, who has expressed concerns that an Islamic minority is failing to integrate into Australian society, has ruled out barring Muslims from immigrating. "I don't believe in abandoning a nondiscriminatory immigration policy," Howard told Macquarie Radio on Tuesday. "That would send the wrong signal to moderate people around the world." "They would feel they are excluded and would feel there was a universal hostility to a particular religious group and I don't think that is helping" the global war on terror, Howard said. But he said moderate Muslims had an obligation to vocally condemn terrorism. "Justifying terrorism by reference to Islam is the common thread of all the terrorist attacks we've had," Howard said.