U.S. President Joe Biden is planning to host a trilateral summit with Japan and South Korea on Aug. 18, Japanese government sources said Thursday, with North Korea's nuclear and missile threats likely to be top of the agenda.

The summit involving Japanese Prime Minister Fumio Kishida and South Korean President Yoon Suk Yeol is expected to be held at the Camp David presidential retreat in Maryland, near Washington, according to the sources.

The three leaders are considering issuing a joint statement after the envisioned talks, the sources said.

Combined photo shows (from L) Japanese Prime Minister Fumio Kishida, U.S. President Joe Biden and South Korean President Yoon Suk Yeol. (Kyodo)

If the plan goes ahead, it will be the first standalone summit between the leaders of the United States, Japan and South Korea, though they have held trilateral meetings on the fringes of international conferences and other occasions.

Biden, Kishida, and Yoon's most recent meeting was in May during a Group of Seven summit in Hiroshima.

But the three-way talks lasted just a few minutes amid a jam-packed schedule. At the time, Biden invited Kishida and Yoon to the United States for an official summit.

When the three leaders next meet, they will likely discuss how to deal with North Korea, which has continued to launch ballistic missiles.

Biden, Kishida and Yoon may discuss a plan for achieving real-time information sharing about the North's missile launches by the end of this year, the sources said.

Currently, Washington has a system that is separately linked to Tokyo and Seoul for detecting and tracking Pyongyang's missiles, but its key Asian security allies do not have a mechanism for immediately sharing such information.

The momentum for closer trilateral relations increased when Yoon visited Tokyo in March, marking the first visit to Tokyo by a South Korean leader in many years. Yoon and Kishida agreed to move on from a long-festering dispute over wartime conscripted labor.

As bilateral relations between Japan and South Korea have improved, the two countries have increased policy coordination with the United States, expanding beyond issues concerning North Korea to include areas ranging from Russia's war against Ukraine to supply chains for critical materials.

Japanese Chief Cabinet Secretary Hirokazu Matsuno said at a press conference, "It is important to further deepen trilateral strategic cooperation in order to uphold the rules-based, free and open international order while responding to North Korea."

The top government spokesman, however, refrained from confirming the specific date of the planned summit.

On Thursday, senior diplomats from Japan, the United States and South Korea held a meeting in Karuizawa, central Japan, and agreed to further reinforce their deterrence and response capabilities against North Korea, according to the Japanese Foreign Ministry.

Takehiro Funakoshi, director general of the ministry's Asian and Oceanian Affairs Bureau, and his U.S. and South Korean counterparts, Sung Kim and Kim Gunn, attended the talks.

Funakoshi told reporters after the talks that the three expressed their "serious concerns" about Pyongyang's fast-paced increase in its missile and nuclear capacities while reaffirming that they are open to dialogue with the North.

At the outset of the gathering, which was open to the media, Sung Kim said the officials will work together in preparation for "the upcoming trilateral leaders summit next month."

Kim also said Washington is "working very hard" to obtain information regarding a U.S. soldier believed to be in Pyongyang's custody after crossing into North Korea from South Korea on Tuesday and "actively engaging to ensure his safety and return."

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