The Pentagon reports it hit four out of five targets in its biggest, most complicated missile defense flight test to date.

The Missile Defense Agency said in a statement that a fifth target - a short-range ballistic missile - did not appear to have been shot down successfully.

The live-fire demonstration was conducted at the US Army's Kwajalein Atoll/Reagan Test Site in Hawaii and surrounding areas in the western Pacific and tested the Aegis Ballistic Missile Defense (BMD), Terminal High Altitude Area Defense (THAAD), and PATRIOT weapon systems.

The THAAD system, produced by Lockheed Martin Corp successfully intercepted its first medium range ballistic target in history, the MDA said.

THAAD is a US Army system designed to shoot down short, medium and intermediate range ballistic missiles with an interceptor that slams into its target.

It can accept cues from Lockheed's Aegis weapons system, satellites and other external sensors and work in tandem with the PATRIOT avanced capability-3 terminal air-defense missile, also built by Lockheed.

In the test, a PAC-3 took down a short-range ballistic missile launched from a mobile platform in the ocean northeast of Kwajalein Atoll, MDA said.

- AP