SEOUL, March 7 (UPI) -- The United States and South Korea are to discuss the deployment of a U.S. anti-missile defense system on the peninsula, but back in 1999, the U.S. Department of Defense concluded a Terminal High Altitude Area Defense-like system could still leave certain portions of South Korea unprotected.
The "Report to Congress on Theater Missile Defense Architecture Options for the Asia-Pacific Region," issued on May 4, 1999, concluded a combination of anti-missile defense systems should be deployed to target incoming missiles from different altitudes, otherwise the system wouldn't provide comprehensive cover.
The report is raising concerns about the ongoing THAAD negotiations between Washington and Seoul, as the technology hasn't changed significantly since the report was issued, South Korean newspaper Hankyoreh reported Monday.
Most "North Korean threats attacking [South Korea] do not fly high enough for exo upper tier systems to engage them," the report read, with "exo upper tier systems" referring to "THAAD-like" interceptor missiles that can destroy incoming missiles from the outer atmosphere, or space.
A "lower-tier system" would need to be deployed since the upper tier cannot intercept any attacks on Seoul, South Korea's most densely populated urban area just 24 miles from the border, as well as the southern portion of the peninsula, the report read.
The addition of as much as 25 land-based lower-tier batteries, similar to the Patriot PAC-3 missiles, would be necessary, the report also stated.
THAAD and its deployment, however, are controversial in the region, and both China and Russia have voiced opposition to its placement on the peninsula. The two countries cited regional surveillance concerns.
The lack of consensus on THAAD "reflects a potentially dangerous escalation of the security situation in Northeast Asia," according to Charles Armstrong, a professor of Korean studies at Columbia University.
The analyst said in February THAAD has "already created a rift between South Korea and China, which of course is exactly what North Korea wants."