SEOUL, South Korea -- South Korea says key parts of a contentious U.S. missile defense system have been installed a day after rival North Korea showed off its military power.

The work to set up the Terminal High-Altitude Area Defense system, or THAAD, within this year has angered North Korea, China and Russia, which see the system’s powerful radars as a security threat.

South Korea said in a statement Wednesday that unspecified parts of THAAD were deployed. The statement said that Seoul and Washington have been pushing to get THAAD working soon to cope with North Korea’s advancing nuclear and missile threats.

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South Korea’s Yonhap news agency says six launchers, some intercept missiles and at least one radar have been deployed.

Seoul says North Korea conducted huge live-fire drills Tuesday.