South Korea's new President Moon Jae-in has been sworn in, vowing to immediately tackle the difficult tasks of addressing North Korea's advancing nuclear ambitions and soothing tensions with the United States and China.
Moon said in his first speech as president on Wednesday he would begin efforts to defuse security tensions on the Korean peninsula and negotiate with Washington and Beijing to ease a row over a US missile defence system being deployed in the South.
In his first key appointments, Moon named two liberal veterans with ties to the "Sunshine Policy" of engagement with North Korea from the 2000s to the posts of prime minister and spy chief.
Moon named Suh Hoon, a career spy agency official and a veteran of inter-Korea ties, as the head of the National Intelligence Service. Suh was instrumental in setting up two previous summits between the North and South.
Veteran liberal politician Lee Nak-yon was nominated to serve as prime minister. Now a regional governor, Lee was a political ally of the two former presidents who held the summits with the North in 2000 and 2007,
Lee's appointment requires parliamentary approval.
Moon was expected to fill the remaining cabinet and presidential staff appointments swiftly to bring an end to a power vacuum left by the removal of Park Geun-hye in March in a corruption scandal that rocked South Korea's business and political elite.
"I will urgently try to solve the security crisis," Moon said in the domed rotunda hall of the parliament building.
"If needed, I will fly straight to Washington. I will go to Beijing and Tokyo and, if the conditions are right, to Pyongyang also."
Spy chief nominee Suh said Moon could go to Pyongyang if it was clear the visit would help resolve the North Korean nuclear crisis and ease military tension on the Korean peninsula.
North Korea is likely to welcome Moon's election but its state media made no mention of his victory on Wednesday.
The deployment of the US Terminal High Altitude Area Defense System (THAAD) in the South has angered China, Seoul's major trading partner, which sees the system's powerful radar as a threat to its security.
The issue has clouded efforts to rein in North Korea's nuclear and missile programs, and also led to recriminations by Beijing against South Korean companies.
Moon, 64, also pledged to sever what he described as the collusive ties between business and government that have plagued many of South Korea's family-run conglomerates, known as chaebol, and vowed to be incorruptible.
"I take this office empty-handed, and I will leave the office empty-handed," he said.
Moon met leaders of opposition parties before his simple swearing-in ceremony at parliament and promised to co-ordinate with them on national security.
Office workers and passersby lined the streets as his motorcade passed through central Seoul en route to the presidential Blue House.
He waved to well-wishers through the sunroof of his limousine, which was flanked by police motorbikes.
Chinese President Xi Jinping and Japanese Prime Minister Shinzo Abe both congratulated Moon on Wednesday.
Xi said China was willing to handle disputes "appropriately" on the basis of mutual trust and understanding.
Abe said he looked forward to working with Moon to improve relations, describing South Korea as one of Japan's most important neighbours.
