Seoul: Tuesday's launch was Pyongyang's second in the past three days and the first since the start of the biggest joint military exercises between South Korea and the US in five years, according to Seoul. In response to growing military and nuclear threats from the North, which has recently carried out a series of increasingly provocative banned weapons tests, Washington and Seoul have stepped up defense cooperation. The Joint Chiefs of Staff issued a statement claiming that North Korea had launched an unidentified ballistic missile towards the East Sea, also known as the Sea of Japan. Also Read: Biden says he anticipates speaking with Xi soon after announcing a submarine deal to confront China Just days before the launch, Pyongyang fired two "strategic cruise missiles" from a submarine in what appeared to be a protest against US-South Korean military exercises. The 10-day Freedom Shield exercise began on Monday as part of an effort by allies to counter North Korea's growing threat. In a rare move, Seoul's military revealed this month that Allied special forces units had been conducting military exercises called "Teak Knives" before Freedom Shield that simulate precision strikes on vital North Korean facilities. According to the aides, the Freedom Shield exercise focuses on the "changing security environment" due to North Korea's increasing aggression. The South Korean military has said they will "incorporate wartime procedures to repel possible North Korean attacks and conduct a stabilization operation in the North". Also Read: In his conversation with Orban, Macron promotes "unity" in Europe The exercise was a "defensive one based on a joint operational plan," it was stressed. However, North Korea has repeatedly threatened to take "coercive" action in response and views all such drills as exercises for aggression. North Korea has declared itself an "irreversible" nuclear power and launched an unprecedented amount of missiles last year. To prepare for a "real war", leader Kim Jong Un earlier this month ordered his military to step up training. Washington has reiterated several times that it is committed to "resolutely" defending South Korea, including using "the full range of its military capabilities, including nuclear". With regard to the US commitment to so-called extended deterrence, in which US military resources, including nuclear weapons, serve to deter attacks on allies, South Korea, for its part, is eager to reassure its increasingly uneasy public . Prior to the exercises, analysts predicted that North Korea would use them as justification for additional missile launches and possibly nuclear tests. It is reasonable to expect additional missile launches with varying styles and ranges, as well as nuclear testing. According to retired South Korean army general Chun In-bum, it shouldn't be shocking if North Korea continues to intimidate. Also Read: US seeks new methods to hold Russian oligarchs accountable for the war Go Myeong-hyun, a researcher at the Asan Institute for Policy Studies in Seoul, said that as an opportunity to demonstrate that "the reason for developing the missile is for self-defense purposes," Pyongyang should take it.