TOKYO, Oct 25 (AFP) - An “unparalleled” scale of response would be warranted if North Korea conducts a seventh test of a nuclear weapon, the United States, Japan and South Korea have warned.

The warning was issued on Wednesday amid concerns by the US and its regional allies that North Korea could be poised to resume nuclear bomb testing for the first time since 2017.

“We agreed that an unparalleled scale of response would be necessary if North Korea pushes ahead with a seventh nuclear test,” South Korean first vice foreign minister Cho Hyun-dong told a news conference in Tokyo.

Cho made his comments alongside Japan’s vice foreign minister Takeo Mori and US Deputy Secretary of State Wendy Sherman.

North Korea has been carrying out weapons tests at an unprecedented pace this year, firing more than two dozen short and medium-range ballistic missiles in recent weeks, including a missile that over-flew Japan.

“We urge (North Korea) to refrain from further provocations,” Sherman said, calling the North’s actions “reckless” and deeply destabilising for the region.

Sherman also said that the US will use its full military capabilities, “including nuclear, conventional and missile defence”, to protect its allies Japan and South Korea.

North Korea needs to understand that the US commitment to the security of South Korea and Japan is “iron clad”, she said.

“And we will use the full range of US defence capabilities to defend our allies, including nuclear, conventional and missile defence capabilities,” she said.

US State Department spokesman Ned Price said in a statement that Sherman also reiterated that the US was continuing to “seek serious and sustained dialogue with the DPRK” (Democratic People’s Republic of Korea) – the official name for North Korea.

Cho, during his talks with Sherman, raised concern that a new North Korean nuclear weapons policy adopted in September increases the possibility of its arbitrary use of nuclear weapons.

“This is creating serious tension on the Korean peninsula,” Cho said.

In September, the USS Ronald Reagan and accompanying ships conducted joint military exercises with South Korean forces in response to a North Korean ballistic missile test in what was their first joint military training involving a US aircraft carrier since 2017.

Angered by South Korea’s military activities, Pyongyang last week fired hundreds of artillery shells off its coasts in what it called a grave warning to its neighbour to the south.

Sherman met earlier on Tuesday with Japan’s Mori and reaffirmed the further strengthening of the Japan-US alliance and other shared goals, including the complete denuclearisation of North Korea and their joint response to China’s increasingly assertive actions in the region.

Japanese defence minister Yasukazu Hamada recently said that North Korea is believed to have achieved a miniaturisation of nuclear warheads while significantly advancing its missile capabilities by diversifying its launch technologies, making interceptions more difficult.

Japan has joined South Korea in also warning of a possible nuclear test by North Korea in the near future.