By Lee Kap-soo

President Yoon Suk-yeol arrived in Washington on Aug. 17 (local time) to attend a trilateral summit with U.S. President Joe Biden and Japanese Prime Minister Fumio Kishida to strengthen security cooperation in the face of North Korea's nuclear threat.

The summit will be held at the Camp David presidential retreat in Maryland on Aug. 18, marking the first time for the three leaders to meet for a trilateral summit.

U.S. President Biden proposed the summit when the three leaders met on the margins of a Group of Seven summit in Japan in May as the U.S. pushes to lock in recently improved Seoul-Tokyo ties in a trilateral framework countering China and Russia's growing assertiveness.

The three leaders plan to adopt two documents -- the "Camp David Principles" and the "Spirit of Camp David" -- with the first one containing sustainable guidelines for trilateral cooperation going forward, and the second outlining their vision for trilateral cooperation and its implementation plan.

In addition to the trilateral summit, Yoon will hold bilateral meetings with Biden and Kishida on Aug. 18. The three leaders will also have lunch together and hold a joint press conference.

Meanwhile, First Lady Kim Keon-hee did not accompany President Yoon this time on the trip to the U.S., which came only hours after the funeral of Yoon's father, Yoon Ki-jung. The late Yoon was an honorary professor at Seoul's Yonsei University and died Tuesday at the age of 92.

The presidential office said Biden and first lady Jill Biden sent condolence flowers to Yoon's hotel, together with a message that read, "You are in our prayers and we wish you peace as you mourn your father."