Photo/Illutration South Korea's newly-elected President Lee Jae-myung takes his oath during his inauguration ceremony at the National Assembly in Seoul on June 4. (Pool Photo via AP)

SEOUL--South Korea’s new President Lee Jae-myung said Wednesday he’ll pursue dialogue with North Korea while bolstering a trilateral partnership with the U.S. and Japan.

He said in his inaugural address a day after his election that his government will deal with potential North Korean aggressions with “a strong deterrence” based on the solid South Korea-U.S. military alliance. But he would also leave the door open for dialogue with North Korea and establish peace on the Korean Peninsula.

He said he’ll pursue pragmatic diplomacy and boost a trilateral Seoul-Washington-Tokyo cooperation based on the South Korea-U.S. alliance.

Lee, who rose from childhood poverty to become South Korea’s leading liberal politician vowing to fight inequality and corruption, won a snap election Tuesday that was triggered by the removal of former President Yoon Suk Yeol over his ill-fated imposition of martial law late last year.

Lee’s term began immediately without the usual two-month transition period after the National Election Commission formally confirmed his victory Wednesday morning.

In a telephone call with Joint Chiefs of Staff Kim Myung-soo, Lee asked the military to closely monitor North Korean moves and maintain a solid readiness based on the combined South Korea-U.S. military alliance, according to local TV footage.

Lee later visited the national cemetery in Seoul to pay respects to late Korean leaders, patriots and war dead who are buried there.