South Korea’s new president offers Pyongyang economic aid for denuclearization

SEOUL—South Korea’s new president said he would keep the door open for dialogue with North Korea and provide support for its fragile economy if Pyongyang stops developing nuclear weapons.

Speaking at his inauguration ceremony on Tuesday, Yoon Suk-yeol, a former prosecutor and newcomer to politics, sought to balance a tough stance against North Korea with the prospect of a breakthrough in the nuclear standoff with the regime of leader Kim Jong Un.

“If North Korea suspends nuclear development and shifts to substantial denuclearization, I will work cooperatively with international society and prepare a bold plan to radically improve North Korea’s economy and the lives of the North Korean people,” he said.

Mr. Yoon begins his presidency facing an array of diplomatic challenges, including North Korea’s nuclear threat and strained ties with China and Japan. He takes office for a single five-year term as the leader of the world’s 10th-largest economy.

Later this month, President Biden will visit South Korea for talks with Mr. Yoon. The North Korean issue will be at the “front and center” of discussions, White House spokeswoman Jen Psaki said on Monday.

During his campaign, Mr. Yoon emphasized military deterrence against North Korea in close alignment with the U.S., a departure from his predecessor Moon Jae-in, who gave priority to dialogue and diplomatic engagement with Pyongyang. Mr. Moon held three summit meetings with Kim Jong Un.

Inter-Korean tensions have been rising again this year, however, after North Korea conducted more than a dozen missile tests, including an inter-continental ballistic missile launch in March and a submarine-launched ballistic missile over the weekend.

During a recent military parade, Kim Jong Un vowed to accelerate the country’s nuclear weapons development. American and South Korean government officials say North Korea appears to be making preparations for its seventh nuclear test as early as this month.

Under previous South Korean presidents, the North has shown little interest in offers of economic help in exchange for denuclearization and Pyongyang has rebuffed repeated recent overtures for talks from both South Korea and the U.S.

Mr. Yoon has also said more field training between the U.S. and South Korea to bolster deterrence is needed after many major exercises were replaced with computer simulations since 2018 in an effort to coax the North into diplomacy. On Monday, the U.S. and South Korea kicked off annual joint air force drills.

The Biden administration’s focus on the war in Ukraine and confronting China will add to the challenge for Mr. Yoon to make progress on North Korean denuclearization, said Park Won-gon, a professor of North Korean studies at Ewha Womans University in Seoul.

“North Korea will continue its missile provocations and Yoon will have to convince Washington to prioritize dealing with the threat,” Mr. Park said.

Mr. Yoon says trilateral security cooperation with Washington and Tokyo is also key to deterring North Korea and has pledged to improve relations with Japan during his campaign. Their ties have worsened over recent years because of disputes that stem from Japan’s 1910 to 1945 colonial rule of the Korean Peninsula.

Japan sent Foreign Minister Yoshimasa Hayashi to Mr. Yoon’s inauguration, the first time Tokyo’s top diplomat has visited Seoul in four years. Mr. Hayashi gave a letter from Japanese Prime Minister Fumio Kishida to Mr. Yoon at a meeting after the inauguration and said the two sides should resolve their disagreements. Mr. Yoon asked the foreign ministers of both countries to work together to improve relations.

Public skepticism in both South Korea and Japan over making concessions to the other side will make it hard to resolve the various disputes, said Choi Eun-mi, a Japan expert at the Asan Institute for Policy Studies in Seoul.

“There will be political gestures to improve bilateral relations once Yoon takes office, but it will be difficult for the two administrations to budge from their basic positions without public consensus,” Ms. Choi said.

Mr. Yoon may also face further strain in South Korea’s relationship with China. He has pledged to add to the U.S.-owned Terminal High Altitude Area Defense missile defense system stationed in South Korea to deter North Korea’s nuclear and missile provocations. Beijing objected to the deployment, saying the system’s powerful radar can reach beyond the Korean Peninsula and spy on China.

Mr. Yoon, a conservative, will face an uphill battle in implementing many of his policies, given that the left-leaning Democratic Party holds a majority in the National Assembly. Nearly 45% of South Koreans say Mr. Yoon won’t perform state affairs well, according to a recent poll. His recent predecessors came into office having attracted favorability ratings of roughly 80% or more.

Write to Dasl Yoon at dasl.yoon@wsj.com