For the first time in a decade, a North Korean has defected to South Korea by crossing the heavily armed border dividing the two countries.  VOA Seoul Correspondent Kurt Achin has more.

South Korean military officials say the North Korean military officer crossed into the South on Sunday.

The officer is being debriefed by South Korean authorities, who are are unwilling to disclose details about the officer's identity.

Technically, North and South Korea remain at war.  A 1953 armistice halted fighting between the two sides after North Korea invaded the South, three years earlier.  That agreement created the demilitarized zone between the two countries, which is nearly impossible to traverse because of guard posts, barbed wire and land mines.

However, there are some points where crossing may be easier, such as the border-straddling village, Panmunjom, where the armistice was signed.  South Korean officials say the officer made his crossing near Panmunjom, where it is possible to simply walk across the border.

About 12,000 North Koreans have defected to South Korea.  Most of them have traveled here by first crossing North Korea's less guarded border to China.  This is the first time a North Korean has successfully walked directly into South Korea since 1998.

Park Sang-ho worked in an intelligence capacity for North Korea before defecting to the South, three years ago.  He advises South Korea on security and intelligence matters.

He says the North Korean who crossed Sunday is a senior officer.

He says the soldier represents a "middle class" among North Korean soldiers, whose mindsets are gradually changing towards the government of North Korean leader Kim Jong Il.  He says this defection will definitely shock North Korean authorities.

Park says soldiers who patrol the South Korean border have a keener interest in what life is like in the South.

He says the border soldiers' proximity to the South increases their curiosity.  As a result they are always trying to learn about South Korea and often listen to radios they own secretly.

Relations between North and South Korea have chilled since the inauguration of conservative South Korean President Lee Myung-bak, who is pushing Pyongyang to improve its human rights policies.  Park says the Lee administration's policies may have been an encouraging factor in the North Korean officer's decision to defect.