China dispatched strategic bombers to South Korea's claimed air defense identification zone this week and delayed responding to a military hotline request, according to a South Korean press report. File Photo by Stephen Shaver/UPI | License Photo

SEOUL, Jan. 12 (UPI) -- A military hotline between China and South Korea was not working when Beijing dispatched 10 strategic bombers and other military aircraft to Korea-claimed airspace on Monday.

While China eventually told Seoul the planes were dispatched for training purposes, South Korea's military said the hotline was not functioning when it initially reached out to Beijing, South Korean news service News 1 reported Thursday.


China told Seoul the planes were dispatched for training, but a South Korea defense official said the planes may have had a "different purpose" and that "further analysis" is needed.

China has taken retaliatory steps to pressure South Korea after it agreed to deploy the U.S. THAAD missile defense system on the peninsula, banning appearances of K-Pop artists and penalizing major South Korean corporations like LG and Lotte.

The Chinese military aircraft that entered Korea's claimed air defense identification zone are capable of being mounted with nuclear warheads, according to the South Korean press report.

But the Chinese advance into the KADIZ is not unprecedented. In 2016, Chinese planes flew into the zone 59 times, 62 times in 2015, and 102 times in 2014.

Neighboring Japan has flown more planes into Korea's claimed zone: 444 times in 2016, 398 times in 2015 and 495 times in 2014, according to South Korea's defense ministry.

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But a military hotline between Korea and Japan has allowed the two countries to lower the possibility of conflict, and a newly signed military agreement, the Japan-Korea GSOMIA, allows the two sides to directly share intelligence.

China's lack of response to a South Korean call on the hotline this week is also raising concerns in Seoul, according to News 1.

China took nearly 15 minutes to respond to South Korea's hotline request on Monday, when the planes were deployed.

Beijing has been reportedly punishing Seoul for its decision to deploy THAAD, but Asia's largest economy is not refraining from pursuing a trilateral free trade agreement with South Korea and Japan, according to South Korean newspaper Herald Business.

A meeting involving trade ministers took place in Beijing this week to negotiate the "overall principles" of the FTA, according to a Seoul trade ministry official.