SEOUL, June 4 (Xinhua) -- Lee Jae-myung was sworn in as South Korea's new president on Wednesday after formally beginning his single five-year term earlier in the day.

The country's 21st president took the oath of office in the National Assembly building, saying in a televised inaugural address that he will serve all people whomever they supported in the presidential election.

Lee of the majority liberal Democratic Party won 49.42 percent of support, defeating his archrival Kim Moon-soo of the conservative People Power Party by a wide margin of 8.27 percentage points.

He stressed that the Asian country was standing at a turning point of great transformation in the face of challenges such as competition for artificial intelligence, climate change, and expanded protectionist moves.

Lee vowed to start with efforts to boost people's livelihoods and revive the faltering economy, saying his government will create new growth engines and share growth outcomes in a fair manner.

The liberal leader noted that his administration will pursue balanced regional development across the country for sustainable growth while actively supporting its cultural industry.

He pledged to build peace on the Korean Peninsula through dialogue and cooperation with the Democratic People's Republic of Korea (DPRK) while protecting people from various accidents such as crowd crushes and airplane crashes.

The president assumed duties without a transition period as he won the snap election, triggered by the removal of his predecessor from office over a botched martial law bid last December.

The scaled-down inauguration event was attended by chiefs of the parliament, the supreme court, the constitutional court and the election watchdog as well as lawmakers and cabinet members.

Before the event, Lee paid tribute at the Seoul National Cemetery where those who made sacrifices for the country are buried.