|Splitting the Korean peninsula roughly in half since the 1950-53 war, the DMZ serves as a buffer zone [EPA]
US President Barack Obama will visit the tense border zone between the two Koreas after arriving in Seoul at a time of renewed nuclear acrimony with North Korea.
On Sunday, the president will also meet South Korean President Lee Myung-Bak to prepare a 53-nation nuclear security summit in Seoul, a day before holding more key talks with China's President Hu Jintao, officials said.
He will also on Monday hold his last meeting as an equal with outgoing Russian President Dmitry Medvedev with whom he masterminded a reset of US ties with the Kremlin, and will see leaders of Turkey and Kazakhstan.
Officials did not say whether Obama was intending to send a message to North Korea with his visit to the Demilitarised Zone (DMZ), but said he would renew his call for Pyongyang to live up to international nuclear standards.
The DMZ is known as the world's last Cold War frontier, and separates the thriving capitalist south from isolated, impoverished communist North Korea which has defied the world with its nuclear drive.
Splitting the two Koreas since the 1950-53 war, the four-kilometer-wide DMZ features guard posts manned by rival armies and barbed wire, and roads bisecting minefields.
Cross-border tension has been high since Seoul accused Pyongyang of torpedoing one of its warships with the loss of 46 lives in March 2010.
The North angrily denied involvement but went on to shell a border island and kill four South Koreans in November the same year.
Obama will visit South Korea at a time of conflicting signals and diplomatic brinkmanship by Pyongyang, now under the untested leadership of Kim Jong-Un who succeeded his late father Kim Jong-Il last year.
Pyongyang has invited UN inspectors to monitor a nuclear freeze deal with the United States, but has also announced it plans a satellite launch which Washington sees as a bid to test new long-range missile technology.
There are 28,500 US soldiers serving in South Korea, a key ally in a region to which Obama has reoriented his foreign policy.