A US aircraft carrier has arrived in South Korea for joint exercises.

In response to North Korea's resumption of significant weapons tests and escalating threats of nuclear confrontation with Seoul and Washington, the allies have reintroduced large-scale military drills that were scaled or delayed in past years to assist dialogue with Pyongyang or because of COVID-19.

The South Korean navy stated that the coordinated training with the Reagan battle group is intended to strengthen the allies' military preparation and demonstrate "the Korea-US alliance's solid commitment for the sake of peace and stability on the Korean Peninsula."

The North Korean menace is also anticipated to be a major topic of discussion when US Vice President Kamala Harris visits South Korea next week following the official burial in Tokyo of killed former Japanese Prime Minister Shinzo Abe.

The Reagan's arrival in South Korea comes after North Korean leader Kim Jong Un warned Pyongyang's rubber-stamp parliament earlier this month that he would never surrender the nuclear weapons and missiles he believes he needs to fight perceived US threats.

North Korea recently enacted a new legislation that formalized its nuclear status and enabled the use of nuclear weapons in a variety of circumstances in which the country or its leadership is threatened.

Sung Kim, the Biden administration's special envoy for North Korea, met with South Korean counterpart Kim Gunn in Seoul on Thursday, expressing "severe worry" over the North's increasing nuclear doctrine outlined in the new legislation, according to South Korea's Foreign Ministry.

The diplomats restated the United States' resolve to protect South Korea with the entire spectrum of its military capabilities, including nuclear weapons, in the event of a nuclear conflict. The allies also reiterated their months-old judgment that North Korea is planning its first nuclear test since 2017 and discussed "stern" responses, according to the ministry.

North Korea has increased weapons testing to a record level in 2022, launching more than 30 ballistic weapons, including intercontinental ballistic missiles, since 2017, capitalizing on a schism in the United Nations Security Council exacerbated by Russia's conflict on Ukraine.

While North Korea's ICBMs receive great attention in the United States because they constitute a possible danger to the American homeland, the North has also been developing its arsenal of nuclear-capable, shorter-range missiles meant to elude South Korean missile defenses.

The North Korean nuclear arsenal's expansion and threats of preemptive nuclear assaults have raised doubts in South Korea about the reliability of the United States' "nuclear umbrella" defending its allies in the event of war.

South Korean President Yoon Suk Yeol, a conservative who entered office in May, has pledged to strengthen South Korea's conventional missile capabilities and to collaborate with the Biden administration to build more effective deterrence methods against North Korean threats.

Senior US and South Korean officials met this month in Washington to examine the partners' deterrent strategy, and released a statement emphasizing that "any (North Korean) nuclear assault will be met with an overwhelming and decisive reaction." According to the statement, the US repeated "its ironclad and unshakable resolve to rely on the entire spectrum of its military capabilities, including nuclear (one)," to provide South Korea with extended deterrence.

North Korea has so far rebuffed requests from the United States and South Korea to resume nuclear negotiations, which has been deadlocked February 2019 due to differences over swapping the removal of US-led sanctions against the North in exchange for the North's disarmament efforts.

Yoon has come under heavy fire from North Korea for continuing military drills with the US and for allowing South Korean activists to use balloons to transport anti-Pyongyang leaflets and other "dirty waste" across the border. According to North Korea, these items were to blame for the COVID-19 outbreak.

South Korean activists have continued to launch balloons after North Korea threatened "deadly" punishment last month, raising fears that North Korea may respond with a nuclear test or border battles.