Applied to North Korea's case, the sunshine policy could be seen in the context of the fact that the communist nation depends for the very survival of its people on the global food aid on which there are now many sanctions; it is only China which provides substantial food aid to North Korea. He also recently called on South Korea to pay one billion dollars for the USA missile defense system now being deployed to the Korean peninsula.
On North Korea, his desire for engagement is at odds with the Trump administration's openness to use force against Kim's regime, which hasn't shown any intention to stop conducting nuclear and ballistic missile tests.
Moon named Suh Hoon, a career spy agency official and a veteran of inter-Korea ties, as the head of the National Intelligence Service.
Moon began his duties earlier in the day by receiving a briefing about North Korea from army Gen.
Lee's appointment requires parliamentary approval.
New South Korean President Moon Jae-in on Friday scrapped a controversial plan to introduce state-issued history textbooks at schools, erasing a key policy of his ousted conservative predecessor Park Geun-hye.
"I will be a president to all people", Mr Moon said in his speech, promising to remain "at eye-level with the people". "If needed, I will immediately fly to Washington". He also said he was willing to visit Pyongyang under favorable conditions.
Moon says he wants to start a dialogue with North Korea, building on the approach of his mentor and former President Roh. Moon competes against twelve other candidates but South Korea presidential elections are decided in a single round.
But North Korea's nuclear weapons program has made remarkable progress since Moon worked for a liberal government that engaged the North with big aid shipments and economic cooperation projects 10 years ago.
Moon met leaders of opposition parties before his simple swearing-in ceremony at parliament and promised to coordinate with them on national security.
"I will take the helm empty-handed and will retire empty-handed", he said.
Chinese President Xi Jinping and Japanese Prime Minister Shinzo Abe both congratulated Mr Moon yesterday.
China has been upset by the Terminal High-Altitude Area Defense system that was approved by Moon's conservative predecessor as a hedge against North Korea, placing Seoul in a hard spot between its closest military ally in Washington and its largest trading partner in Beijing. The THAAD is increasingly opposed among many South Koreans, particularly based on Trump's calls for them to pay for it.
Moon responded that he's aware of China's concerns and he hopes the two countries can have a greater understanding of each other's positions on the system, it said.
But former USA officials held two days of informal talks in Oslo, Norway, this week with a Pyongyang delegation led by Choe Son Hui, a senior diplomat for North America. The person wasn't authorized to publicly discuss the diplomacy and demanded anonymity.
The North Koreans often use the occasional talks to take the temperature of the USA government, since the two sides have had little direct contact in recent years. The American participants typically report their observations to the US administration.