US President Joe Biden has met with the leaders of Japan and South Korea to co-ordinate their response to North Korea’s threatening nuclear and ballistic missile programmes, as well as to seek input on managing China’s assertive posture in the Pacific region on the eve of his planned face-to-face with President Xi Jinping.

Mr Biden met separately with Japanese Prime Minister Fumio Kishida and South Korean President Yoon Suk Yeol, before all three sat down together on the side-lines of the East Asia Summit in Cambodia.

He opened by offering condolences for a crowd surge during Halloween festivities in Seoul that killed more than 150 people, saying the US had grieved with South Korea.

He added: “We face real challenges, but our countries are more aligned than ever.”

Both Mr Yoon and Mr Kishida discussed the ongoing displays of aggression by North Korea, which has fired dozens of missiles in recent weeks.

The launches include an intercontinental ballistic missile 10 days ago that triggered evacuation alerts in northern Japan, and the allies warn of a looming risk of the isolated country conducting its seventh nuclear test in the coming weeks.

US National Security Adviser Jake Sullivan said Mr Biden aimed to use the meetings to strengthen the three countries’ joint response to the dangers posed by North Korea, officially known as the Democratic People’s Republic of Korea (DPRK).

Fumio Kishida and Yoon Suk Yeol
Japan’s Prime Minister Fumio Kishida, right, and South Korean President Yoon Suk Yeol met US leader Joe Biden (Vincent Thian/AP)

He said: “What we would really like to see is enhanced trilateral security co-operation where the three countries are all coming together.

“That’s acutely true with respect to the DPRK because of the common threat and challenge we all face, but it’s also true, more broadly, about our capacity to work together to enhance overall peace and stability in the region.”

Tensions on the Korean peninsula have skyrocketed in recent months as the North continues its weapons demonstrations and the US and South Korea launched stepped-up joint defence exercises.

Earlier this month, the South Korean military said two B-1B bombers trained with four US F-16 fighter jets and four South Korean F-35 jets during the last day of “Vigilant Storm” joint air force drills.

It was the first time since December 2017 that the bombers were deployed to the Korean Peninsula. The exercise involved a total of roughly 240 warplanes, including advanced F-35 fighter jets from both countries.

North Korea responded with its own display of force, flying large numbers of warplanes inside its territory.

The Biden administration has said it has sent repeated requests to negotiate with North Korea without preconditions on constraining its nuclear and ballistic missile programmes, but Kim Jong Un’s government has not responded.

Mr Biden has said he plans to press Mr Xi to use China’s unique sway over North Korea to curtail its aggressive behaviour, as part of what is expected to be a wide-ranging bilateral meeting on the margins of the G20 gathering in Bali, Indonesia.

Xi Jinping
Joe Biden is to meet Chinese President Xi Jinping in person for talks on Monday (Andy Wong/AP)

China “has an interest in playing a constructive role in restraining North Korea’s worst tendencies”, Mr Sullivan said on Saturday, but cautioned: “Whether they choose to do so or not is, of course, up to them.”

Mr Biden told reporters on Sunday that he has “always had straightforward discussions” with Mr Xi, and that has prevented either of them from having “miscalculations” of their intentions.

Their meeting comes weeks after Mr Xi cemented his grip on China’s political system with the conclusion of the Community Party congress in Beijing that gave him a norm-breaking third term as leader.

“His circumstances changed, to state the obvious, at home,” Mr Biden said of Mr Xi.

Mr Biden maintained that his own have as well, saying that after Democrats retained control of the Senate in the midterm elections, “I know I’m coming in stronger”.

Monday’s meeting will be the first in-person sit-down between the leaders since Mr Biden was elected to the White House. US officials in the past have expressed frustration that lower-level Chinese officials have proven unable or unwilling to speak for Mr Xi, and are hoping the face-to-face summit will enable progress on areas of mutual concern – and, even more critically, a shared understanding of each other’s limitations.

“I know him well, he knows me,” Mr Biden said. “We’ve just got to figure out where the red lines are and what are the most important things to each of us, going into the next two years.”