Seoul, Jumada I 2, 1433, Mar 25, 2012, SPA - US President Barack Obama on Sunday made his first visit to the demilitarized zone on the North-South Korean border. The visit, made on the first day of a three-day trip in South Korea, was meant to show the US security commitment to South Korea, where Washington has stationed 28,500 of its troops, the White House was quoted as saying by DPA. "You guys are at freedom's frontier," Obama told US soldiers. "... The contrast between South Korea and North Korea could not be clearer, could not be starker, both in terms of freedom but also in terms of prosperity." Obama spent about 10 minutes on an observation platform at the Korean border and looked into North Korean territory through binoculars, South Korea's Yonhap News Agency reported. Obama is to meet later in the day with his South Korean counterpart, Lee Myung Bak, before both men attend the Nuclear Security Summit. The gathering Monday and Tuesday in Seoul, which is to bring together more than 50 countries, is meant to secure the world's nuclear material. --SPA 10:57 LOCAL TIME 07:57 GMT www.spa.gov.sa/982667