Lee Jae-myung, the newly elected president of the Republic of Korea, pledged to promote national unity, revive the economy and restore peace in his first speech to the nation as the country's top leader on June 4.

"It is time to revive a nation pushed to the brink, restore growth and create a future where everyone can live happily," Lee said during the inauguration ceremony held at the National Assembly.

Instead of the blue tie he wore during the campaign, Lee wore a multi-colored tie that comprised white, red and blue at the inauguration ceremony.

Delivering a speech after taking his oath, Lee said, regardless of whom each voter supported in the election, he will become "the president for all" who embraces and serves every citizen in line with the call for unity.

Lee of the liberal Democratic Party officially began his single five-year presidential term at 6:21 am on June 4, after the National Election Commission confirmed the voting results, according to Yonhap News Agency.

In the election held the previous day, Lee won 49.42 percent, defeating his rival Kim Moon-soo of the People Power Party by 8.27 percentage points.

The election came at a time when the ROK had gone through months of political vacuum following former president Yoon Suk-yeol's Dec 3 martial law declaration.

"The Lee Jae-myung administration under the Democratic Party will be a just and inclusive government, as well as a pragmatic and flexible one," Lee said.

Lee said he will become a president who ends the political division and uses national unity as the driving force to create a society that continues to grow and develop.

He said an emergency economic response task force will be launched immediately to improve people's livelihoods. He also vowed to promote more balanced and just development for shared prosperity.

Lee also said he will open channels of communication with the Democratic People's Republic of Korea and establish peace on the Korean Peninsula through dialogue and cooperation.

"Safety is as essential as food and peace is the foundation of the economy," Lee said, noting that peace gained without fighting is the surest security.

After the inauguration ceremony, Lee walked outside the National Assembly and greeted the public that gathered in front of the lawn.

Lee, 61, was a human rights lawyer for two decades before joining politics in 2005.

He made the first attempt to run for presidency as a DP candidate in 2017, but lost to former president Moon Jae-in in the primary. He later succeeded in securing the party's candidacy in the 2022 presidential election, but lost to Yoon by a narrow margin of 0.7 percent.