U.S. bases 28,000 troops in S. Korea

American presence, military exercises are sore spot for North

There are about 28,000 American troops and civilian military personnel assigned to U.S. Forces Korea, although the number fluctuates during military exercises and when a new unit moves in to relieve another.

The numbers can dip to about 27,000 or top off at 33,000, according to Army Col. Chad Carroll, a spokesman for U.S. Forces Korea.

South Korea has a military of about 650,000 troops.

U.S. troops based in South Korea and the joint military exercises they conduct each year have long been an issue for North Korea, whose leader Kim Jong Un is set to meet in Singapore with President Trump on Tuesday.

The Army has the most troops of the services: more than 19,000 soldiers. The Air Force has more than 8,000 airmen, the Navy as many as 1,000 sailors and the Marine Corps about 200 Marines.

The majority of troops are at U.S. Army Garrison Humphreys in Pyeongtaek; Yongsan in Seoul; and Camp Walker in Daegu.

The Air Force has two bases, Osan and Kunsan. The Navy operates from Busan and Jinhae.

The U.S. military is moving most of its forces from bases near the border with North Korea to bases farther to the south.

The mutual defense treaty between the United States and the Republic of Korea, in effect since the early 1950s, commits the United States to help South Korea defend itself.

South Korea pays about half of the costs of keeping U.S. troops stationed there. In 2016, that amounted to $821 million.

In 1950, U.S. troops fought to prevent a North Korean seizure of South Korea. More than 33,000 American troops were killed and more than 100,000 were wounded during the three-year war that was suspended by an armistice agreement.

Last year, after North Korea tested long-range ballistic missiles, the South Korean government agreed to deploy the Terminal High Altitude Area Defense (THAAD) ballistic missile defense system.