North Korea has fired a ballistic missile towards its eastern waters, according to officials in Seoul, hours after threatening a “harder military response” to US efforts to boost its security presence in the region.

South Korea’s Joint Chiefs of Staff said the short-range ballistic missile was fired from North Korea’s Wonsan area on Thursday.

The missile flew about 240 kilometers (149 miles) and reached an altitude of 47 kilometers (29 miles), the JCS said, adding that the South Korean and US militaries had conducted a “pre-planned” missile defense exercise to shortly before the launch. .

The South Korean military will continue to maintain a ready posture, he said.

Pyongyang has tested a the highest number of missiles this year, including an intercontinental ballistic missile that could fail, although Washington and Seoul expanded scope and scale for their joint military exercises.

Japan was involved in some of the drills.

Amid the tension, the leaders of the US, South Korea and Japan held trilateral talks on the sidelines of the East Asia Summit in Cambodia last week and pledged to work together to further “strengthen deterrence”.

In a statement after the discussion, US President Joe Biden, South Korean President Yoon Suk-yeol and Japanese Prime Minister Fumio Kishida strongly condemned North Korea’s “unprecedented number of ballistic missile launches” and pledged “closer trilateral ties still to be created, in the field of security and beyond”.

They also warned Pyongyang against conducting a seventh nuclear test, with Biden reiterating that the US commitment to the defense of Seoul and Tokyo was “backed by the full range of capabilities, including nuclear”.

North Korea condemned the trilateral summit on Thursday, with Foreign Minister Choe Son Hui saying the three countries’ “war drills for aggression” would not stay in Pyongyang, but would pose a “more serious, realistic and inevitable” on themselves.

“The sharper the US is on the ‘reinforced offer of extended deterrence’ to its allies and the more it intensifies provocative and bluffing military activities … the more severe the DPRK’s military response will be,” Choe said in a statement. made the official KCNA news agency.

She referred to her country by the initials of its official name, the Democratic People’s Republic of Korea.

“The United States will know very well that this is a gamble, and they will certainly regret it,” she said.

Choe added that the North’s military actions are “legitimate and just reactions” to the US-led drills.

Analysts said that the signals coming from Pyongyang were significant because of the regional summit last week, and The participation of the President of China Xi Jinping after years of self-imposed pandemic isolation.

China is the North’s main ally and remote trading partner.

“Beijing may not immediately become more cooperative in dealing with North Korea, even after the Kim regime conducts another nuclear test,” Leif-Eric Easley, a professor at Ewha University in Seoul, told Al Jazeera via email.

“But at some point, Chinese interests would prefer to pressure Pyongyang rather than face a more strategically united US, South Korea and Japan.”