SEOUL (Reuters) - U.S. Defense Secretary Jim Mattis said on Friday there has been no change in U.S. policy protecting South Korea, in the face of missile and nuclear threats from the reclusive North, after a meeting with South Korean President Moon Jae-in. In a press release distributed by South Korea s presidential office after the meeting, Mattis was also cited as saying North Korea s obsession with its weapons programs presented a threat to the United States as well as South Korea. 