But after the North Korea-U.S. diplomacy collapsed in 2019, Moon has faced withering criticism that his engagement policy only helped North Korea buy time and prefect its weapons program in the face of U.S.-led sanctions and pressure campaign on the North.
Pyongyang eventually urged Moon not to interfere in its dealings with the United States and unleashed crude insults on him.
In his last speech, Moon claimed his government helped ease the danger of war on the Korean Peninsula and bring up hopes for peace through diplomacy.
“The reason why we failed to move forward further wasn’t because we lacked efforts and a determination to do that. There was a barrier that we can’t overcome only with our determination. It’s a barrier that we should overcome,” Moon said, without clarifying what the obstacle was.
Last month, Moon and Kim exchanged their final official letters expressing hope for improved bilateral relations. But some experts say the way North Korea described the letters, in which it highlighted Moon's vow to continue campaigning for Korean reunification even after leaving office, reflected its intent to divide public opinion in South Korea and discourage Seoul's new government from taking a hard line toward Pyongyang.
During a massive military parade in Pyongyang three days after the letter exchange was announced, Kim pledged to speed up the development of his nuclear weapons and threatened to use them proactively if provoked. In recent months, Kim's military has also been test-launching a spate of missiles targeting South Korea, Japan or the mainland U.S.
Some experts say Kim aims to rattle Yoon's incoming government while modernizing his weapons arsenal and pressuring the Biden administration into relaxing sanctions on it. South Korean officials say North Korea also appears to be preparing for its first nuclear test since 2017.
Associated Press writer Kim Tong-hyung contributed to this report.