WASHINGTON, Oct. 12 (Yonhap) -- South Korean President Lee Myung-bak paid an unprecedented visit to the Pentagon on Wednesday and received a briefing from top American military officials on North Korea and other security issues, the presidential office said.

Lee is the first South Korean president to visit the Pentagon.

The previously unscheduled event was organized after the U.S. invited Lee, saying it wants to brief him on Washington's position regarding the security situation on the Korean Peninsula, the presidential office said.

"The U.S. government's invitation of President Lee to the Pentagon is an act of showing respect to the head of state of the ally South Korea and reaffirming the firm U.S. commitment to security on the Korean Peninsula," a presidential official said.

The U.S. participants in the meeting included Defense Secretary Leon Panetta, Joint Chiefs of Staff Chairman Martin Dempsey, and all other top American military commanders, such as the chiefs of the Army, Navy and Air Force, the office said.

Lee arrived in Washington on Tuesday for a five-day state visit that includes talks with U.S. President Barack Obama and an address to a joint session of Congress. The trip coincided with the upcoming U.S. ratification of a long-pending free-trade agreement between the two countries.

The United States fought alongside South Korea against invading troops from North Korea during the 1950-53 Korean War. The conflict ended in a truce, not a peace treaty, leaving the divided peninsula still technically at war.

About 28,500 American troops are currently stationed in South Korea to help deter the North.