Obama visits South Korea

Obama visited US troops at the border between South and North Korea in a show of support for Seoul as nuclear tensions rise in the region.

North Korea announced last week that it would launch a rocket into orbit in April, fuelling fears of nuclear developments in the communist country.

"You guys are at freedom's frontier," Obama told troops at a US base on the edge of the Demilitarized Zone (DMZ). "The contrast between South Korea and North Korea could not be clearer, could not be starker, both in terms of freedom and in terms of prosperity."

Whilst visiting the border, Obama spent about 10 minutes on an observation platform and looked into North Korean territory through binoculars, South Korea's Yonhap News Agency reported.

Obama will take part in a two-day global summit on nuclear security hosted by South Korea, which is set to start on Monday. The focus of the summit is atomic terrorism, but the nuclear standoff with North Korea and Iran, as well as North Korea's planned launch, will likely dominate discussions.

Nations criticize planned launch

Washingtonhas condemned North Korea's plan to launch the Kwangmyongsong-3 satellite into orbit on an Unha-3 rocket in April. The launch is scheduled to mark the 100th birthday of the isolated, highly militarized communist state's deceased founder, Kim Il-Sung.

North Koreaannounced its plan just three weeks after making a deal with the US, under which the North agreed to observe a partial nuclear freeze and missile test moratorium in return for food aid.

The United States, Australia and other nations are concerned that the launch could be a pretext for a long-range missile test. Washington has condemned the plan as a violation of North Korea's promise to halt long-range missile launches, nuclear tests and uranium enrichment.

The UN Security Council passed a resolution banning such tests after North Korea staged missile and nuclear tests in 2009.

Obama seeks support

More than 50 other world leaders are expected to participate in the talks starting on Monday. The summit is the follow-up to the first nuclear security summit Obama held in Washington in 2010.

Iran's continued nuclear developments are also threatening the disarmament agenda and drawing international criticism.

Obama will meet with South Korean President Lee Myung-Bak in Seoul later Sunday for talks.

He will then hold talks on Monday with China's President Hu Jintao and outgoing Russian President Dmitry Medvedev on the sidelines of the Seoul summit, where he hopes to win their support in pressuring Pyongyang.

Chinais the North's key ally. It and Russia - along with South Korea, Japan and the United States - are involved in stalled negotiations which began in 2003 on scrapping Pyongyang's nuclear weapons program.

North Korea, meanwhile, has denounced the Seoul summit as a "burlesque" intended to rally world opinion against its nuclear program.

tm/dfm (Reuters, AP, AFP, dpa)