South Korean and US defense officials said Sunday they would begin formal talks on the deployment on the Korean peninsula of a US missile defense system to counter the growing threat from North Korea.

South Korean and US defense officials said Sunday they would begin formal talks on the deployment on the Korean peninsula of a US missile defense system to counter the growing threat from North Korea.

The announcement followed a North Korean rocket launch that the US and its allies condemned as a covert ballistic missile test.

"It has been decided to formally start talks on the possibility of deploying the THAAD system to South Korea as part of steps to bolster the missile defense of the Korea-US alliance," said Yoo Jeh-Seung, the South's deputy defense minister for policy.

There has been speculation for years about the deployment of the Terminal High Altitude Area Defense (THAAD) system -- one of the most advanced in the world -- to the South, one of Washington's main Asian allies.

The US insists that it is a deterrent necessitated by the North's advancing ballistic missile program, while China and Russia argue that it would undermine stability and could trigger an arms race in a delicately balanced region.

"The Korea-US alliance had no choice but to take such a defense action because North Korea staged a strategic provocation and is refusing to have a genuine dialogue on de-nuclearization," Yoo said in a joint briefing with Lieutenant General Thomas Vandal, commander of the US Eighth Army based in the South.

Vandal argued that it was "time to move forward" with the THAAD issue, claiming there was "growing support" in the South for its deployment.

Pyongyang says any such move would be a Cold War tactic to "contain" China and Russia.

But Yoo stressed the THAAD system -- if deployed -- would "operate only regarding North Korea".