SEOUL, South Korea — China's ambassador to South Korea warned Tuesday that the planned deployment of a US missile defense system in the country could damage Beijing-Seoul ties, possibly irreparably.
Once damaged, it would be "hard" to normalize relations between the two former Cold War enemies, Ambassador Qiu Guohong said, according to a spokesman for South Korea's main opposition Minju party.
Qiu made the remarks when he met Minju party head Kim Jong-In at parliament. A spokesman for the Chinese embassy said the Minju party's briefing on the meeting to journalists was accurate.
"It has taken much effort to develop China-South Korea ties to this degree. But these efforts could be destroyed in an instant because of one issue," Qiu said in reference to the planned deployment of the advanced US missile defense system in South Korea.
China has repeatedly protested since Washington and Seoul announced plans to install the Terminal High Altitude Area Defense system (THAAD) in the South, in response to North Korea's recent nuclear test and rocket launch.
But Tuesday was the first time that a Chinese diplomat or official has warned of the effect on diplomatic ties with Seoul.
Qiu repeated Beijing's argument that the THAAD deployment would "greatly undermine" China's security interests, cause instability and spark a regional arms race.
"(South Korea) should consider whether its own security, under these circumstances, could be guaranteed," Qiu said.
China fought alongside North Korea against the South and its allies during the 1950-53 war.
It established diplomatic ties with Seoul only in 1992 but is now the South's top trading partner.
Earlier on Tuesday South Korea's defense ministry said Washington and Seoul had postponed the signing of an accord, originally due on Tuesday, on setting up a joint working group to discuss details of the THAAD deployment.
The delay comes as Chinese Foreign Minister Wang Yi is set to visit Washington from Tuesday to meet his US counterpart John Kerry for possible talks on the controversial missile defense system and on North Korea.
The THAAD system fires anti-ballistic missiles to smash into enemy missiles either inside or outside the Earth's atmosphere during their final flight phase.
The interceptor missiles carry no warheads, instead relying on kinetic energy to destroy their targets.
The allies announced their intention to begin talks on its deployment following Pyongyang's long-range rocket launch on Feb. 7, which was seen by the US and its allies as a covert ballistic missile test.
China's foreign ministry spokeswoman Hua Chunying warned Monday the deployment of THAAD should not be used as a front to "undermine China's own legitimate (security) interests."
The South's defense ministry reiterated Tuesday that the US system only targets North Korean missiles and that its deployment was an issue between the two allies.
The ministry said it expects official talks on THAAD to begin next week once the two sides set up the joint working group later this week.