North Korea on Monday fired two ballistic missiles, which the country claimed is capable of destroying an “enemy operational airfield,” a day after South Korea and the US staged combined aerial drills in a show of the alliance’s readiness to respond to Pyongyang’s launch of an intercontinental ballistic missile.

The two missiles were fired toward the East Sea from the area of Sukchon County, South Pyongan Province, between 7 a.m. and 7:11 a.m. The two traveled around 390 kilometers and 340 km respectively, before splashing down off the east coast of the peninsula, South Korea’s Joint Chiefs of Staff said, without further details.

North Korean state media promptly reported that the missile launches on Monday were in response to the combined aerial drills between South Korea and the US that were conducted in South Korean airspace on Sunday.

The air exercise -- which involved the US’ B-1B strategic bombers, the South Korean Air Force’s F-35A stealth fighters and other fighter jets -- was staged, one day after North Korea fired what the country claimed to be a Hwasong-15 ICBM on Saturday afternoon.

State media said the long-range artillery unit of the Korean People’s Army on the western front fired two projectiles using the 600 mm multiple-launch rocket system, MLRS, which struck virtual targets set 337 km and 395 km away from the launch site.

North Korea seems to be simulating targeting air bases in South Korean territory within the strike range, including the South Korean air base in the city of Cheongju, North Chungcheong Province, which is home to F-35A stealth fighter jets, as well as the US Air Force’s Osan Air Base in the city of Pyeongtaek, Gyeonggi Province, and Kunsan Air Base on the west coast in North Jeolla Province.

North Korean state media also underscored that the 600 mm MLRS with a large diameter is a “precision attack weapon system” capable of carrying and firing tactical nuclear weapons or small nuclear warheads designed to be used on the battlefield. The 600 mm “super large-caliber“ MLRS is dubbed as the KN-25 short-range ballistic missile by the US.

“It is a tactical nuclear attack means boasting of the great might powerful enough to assign only one multiple rocket launcher with four shells so as to destroy an enemy operational airfield,” KCNA said in an English-language version, claiming that the North Korean military can paralyze the operation of air bases only with four rockets.

“The KPA fully demonstrated its full readiness to deter and counter the US and South Korean combined air force bragging about their air superiority.”

Kim Yo-jong, North Korean leader Kim Jong-un’s sister and a vice department director of the Party Central Committee, also reinstated Pyongyang’s principle of taking “corresponding counteraction” to the deployment of US strategic assets “if it is judged to be a direct or indirect threat” to the country.

“The frequency of using the Pacific as our firing range depends upon the US forces’ actions,” Kim said in an English language statement.

“We affirm once again that there is no change in our will to make the maniacs escalating the tensions pay the price for their action.”

Kim also notably refuted the assessment of South Korean experts who cast doubts over North Korea’s ICBM technologies. Kim specifically denounced experts for raising questions about whether North Korea has the capabilities to swiftly launch liquid-propellant ballistic missiles using the method of “ampulization” and master ICBM reentry vehicle technologies to protect a warhead.

Hong Min, director of the North Korean Research Division at the government-funded Korea Institute for National Unification, said North Korea appears to have achieved the two major goals by issuing two separate statements and elaborating its goal of firing projectiles from the 600 mm-caliber MLRS prior to the allies’ annual military exercises scheduled for March.

“In a nutshell, North Korea seeks to enhance the reliability of strategic nuclear weapons developed to target the US mainland and to show its confidence in operating tactical nuclear weapons on the battlefield in the run-up to combined South Korea-US military exercises,” Hong told The Korea Herald.

“Given that the Hwasong-15 is North Korea’s so-called strategic weapon that can strike the US mainland, it is a very crucial weapon system that can show North Korea’s capabilities to deter the US. In this sense, North Korea showed a hypersensitive response on the credibility of the Hwasong-15,” Hong added.

Echoing the view, Park Won-gon, a professor of North Korean Studies at Ewha Womans University, Kim Yo-jong “made rebuttals for fear of failing to achieve North Korea’s political goal of the Hwasong-15 launch” as ICBM capabilities were publicly challenged and questioned. The launch aimed to prove the reliability of its capabilities to hit the US mainland.

“North Korea has been waging a struggle for recognition with Kim Yo-jong coming to the front and personally making reference to technological issues,” Jung Dae-jin, a professor at Halla University in Wonju, Gangwon Province, told The Korea Herald.

Hong also took note of the significance of North Korea’s exceptional and specific disclosure of how to operate the 600 mm MLRS to strike key targets such as air bases in South Korean territory in case of contingency on the Korean Peninsula.

“North Korea publicized its operational concept of attacking air bases with tactical nuclear weapons to counter the overwhelming air superiority of South Korea and the US,” Hong said.

“North Korea also forewarned that it will stage live-fire exercises to respond to South Korea-US military exercises and overpower them.”

North Korean media previously claimed the deployment of 30 600 mm super-large multiple-rocket launchers to the military by reporting a ceremony of weapons delivery held on the last day of 2022. The North Korean leader said the MLRS will “carry out its combat mission of overpowering the enemy as a core, offensive weapon” of North Korean armed forces.

But the South Korean military on Monday said that North Korea has not acquired miniaturized, tactical nuclear weapons that can be mounted on the 600 mm MLRS.

Overall, Jung said the North Korean missile launches were expected in light of its “principle of strength-for-strength” repeatedly affirmed by the North Korean leader.

“North Korea will go all out to respond to the South Korea-US combined exercises by ramping up its aggressive rhetoric and taking tit-for-tat military action.”

Park also pointed out that Monday’s missile launch came after Kim Yo-jong on Sunday warned that North Korea will “take corresponding and very powerful and overwhelming counteraction” against every hostile move to North Korea, delegated by the North Korean leader.

“As Kim Jong-un’s instruction must be fulfilled, North Korea has taken corresponding and overwhelming tit-for-tat action against everything.”

North Korea’s missile launches also could be part of the Kim Jong-un regime’s strategy to consolidate internal unity at a juncture when South Korea’s Unification Ministry assesses that its food crisis has deteriorated and people in some regions have continued to die from hunger.

“North Korea has been aware that South Korea and the US will not stop making efforts to strengthen their readiness posture against North Korean provocations. Therefore, North Korea exploits the direction as an excuse to advance nuclear capabilities and step up internal control,” Park said.