U.S. President Barack Obama and South Korean President Park Geun-hye said Washington and Seoul are taking steps toward a comprehensive global alliance while remaining rooted in security ties that recognize North Korea's nuclear provocations as the "biggest threat to the Korean peninsula." UPI reported. "I want to reaffirm the commitment of the United States to the defense and security of the Republic of Korea will never waver," President Obama said at a joint press conference at the White House on Friday. "Our alliance remains a linchpin of peace and security not just on the Korean peninsula but across the region."