Yoon Suk-yeol, who was inaugurated as South Korea's president on Tuesday, comes to office promising a harder line on North Korea and closer relations with the U.S.

What he's saying: He has vowed to "firmly deal with illicit, unreasonable behavior by North Korea" but "leave open the door for South-North talks" — a pledge the conservative leader emphasized during his inauguration, along with an "audacious plan" to bolster Pyongyang's economy if it commits to full denuclearization.

• "While North Korea's nuclear weapon programs are a threat, not only to our security but also to Northeast Asia, the door to dialogue will remain open so that we can peacefully resolve this threat," Yoon said outside parliament in Seoul, per AP.
• "If North Korea genuinely embarks on a process to complete denuclearization, we are prepared to work with the international community to present an audacious plan that will vastly strengthen North Korea’s economy and improve the quality of life for its people," he added.

State of play: The former public prosecutor and political newcomer takes power under fairly ominous circumstances. North Korea has conducted 14 missile tests already this year, including the first ICBM test since 2017.

• Supreme Leader Kim Jong-un promised to expand his nuclear arsenal "at the fastest possible speed​" during a military parade last month. Kim has also said Pyongyang is pursuing lower-yield, "tactical" nuclear weapons, which could lower the threshold for a nuclear strike.
• In a shift from his dovish predecessor Moon Jae-in, Yoon has said he would respond to an imminent North Korean nuclear attack with a preemptive strike.

Context: Moon made detente with Pyongyang his overriding foreign policy priority, and tried to carefully balance relations with Washington and Beijing.

• Yoon, by contrast, promised to make strengthening the alliance with Washington "the central axis" of his foreign policy, promised to take a tougher line on China and condemned Moon's approach to North Korea as "parochial and shortsighted" in a Foreign Affairs essay earlier this year.
• He also plans to improve relations with Japan, speak up about human rights abuses and raise South Korea's profile on issues well beyond the North Korea.
• But he'll face many of the same constraints Moon did, particularly towards China, which is South Korea's largest trading partner and a crucial player on North Korea.

Driving the news: One step announced last week during the presidential transition might signal a greater willingness in Seoul to step on Beijing's toes. South Korea's intelligence agency became the first Asian member of NATO's cyber defense organization.

• China fiercely opposes any NATO presence in the region, and the Global Times tabloid warned that the U.S. was pushing its South Korean "chess piece" into a step that "might trigger more confrontation with its neighbors."

What to watch: Beyond laying out a general policy framework, insisting he's ready to talk with no conditions, and criticizing each missile test as they come, President Biden has hardly publicly engaged on North Korea.

• With the odds of a diplomatic breakthrough looking slim, the administration seems to be focused on limiting the likelihood of serious escalation.
• But Kim may seek to test Yoon and force his way onto Biden's agenda soon, perhaps with a nuclear test.

Editor's note: This article has been updated with comment from Yoon.