North Korea's latest launch of a long-range rocket prompted Seoul and Washington to begin talks on the deployment of an advanced U.S. missile defense system in South Korea, a move that has been strongly opposed by the North's important ally, China.

North Korea said Sunday it successfully put a satellite into orbit, but the international community swiftly condemned the launch as a covert test of ballistic missile technology, which is banned under U.N. resolutions.

China's reaction to North Korea's rocket launch was somewhat muted, expressing "regrets." At the same time, China summoned South Korea's ambassador and protested against the decision to start talks on the deployment of a Terminal High-Altitude Area Defense (THAAD) battery to South Korea.

Currently, South Korea has no defense assets to intercept North Korean missiles at high altitudes.

With North Korea continuing to develop its nuclear and missile arsenals, analysts in Seoul say South Korea has no choice but to adopt the THAAD battery, which would be deployed at a U.S. base in South Korea, home to about 28,500 American troops.

Even before North Korea's fourth nuclear test on Jan. 6 and the Sunday rocket launch, China has publicly opposed the deployment of the THAAD battery to South Korea, arguing that it could also target China.

Yun Duk-min, head of the Korea National Diplomatic Academy, refuted the Chinese claim, saying the THAAD battery is defensive in nature.

"I think that China has been using the THAAD issue to make a rift in the Korea-U.S. alliance," Yun said. "Basically, the U.S. military is stationed in South Korea, and there is a Korea-U.S. alliance. Given these factors, the THAAD issue is relatively immaterial."

"If China worsens ties with South Korea because of the THAAD issue, it would not be a wise decision for China," Yun said.

China, North Korea's diplomatic and economic lifeline, has resisted calls to hand down crippling economic sanctions on North Korea following its latest nuclear test.

Analysts say China's leadership is reluctant to impose tougher sanctions on North Korea because a sudden collapse of the regime could spark a refugee crisis at its border and lead to a pro-U.S., democratic Korea on its doorstep.

 Kim Heung-kyu, head of the China Policy Institute at South Korea's Ajou University, said relations between South Korea and China face a test because Beijing views the THAAD battery as a way of strengthening the alliance with Seoul, Washington and Tokyo.

"China does not regard the THAAD system as an issue of missile or radar, but a 'regional alliance' among South Korea, the U.S. and Japan," Kim said. South Korean and U.S. officials made it clear that the THAAD battery, if deployed, "would be focused solely on North Korea."

Still, there is a risk that the deployment of the THAAD battery in South Korea could make it difficult for Seoul to seek Beijing's cooperation against Pyongyang, Kim said.

"With regard to the denuclearization of North Korea, I am not positive about whether the THAAD system is a useful option or not," Kim said. (Yonhap)