SEOUL — The Republic of Korea's President Lee Jae-myung vowed on Thursday to implement a "bold" fiscal policy to boost a flagging economy after the country's martial law crisis and to tackle challenges posed by looming US tariffs.

Lee, who was elected on June 3 in a snap election, said it was his top priority to improve the lives of the people, whose faith in government had been greatly shaken by "a national crisis" that hammered Asia's fourth-largest economy.

"It is a time when the proactive and bold role of national finance is more important than ever," Lee, who has pledged to implement expansionary fiscal policy, said in his opening remarks at a news conference to mark 30 days in office.

His administration has proposed $14.7 billion of extra government spending to support sluggish domestic demand. Parliament, controlled by his Democratic Party, is expected to vote on the budget bill soon.

Lee also said he was doing his best to achieve a "mutually beneficial and sustainable" outcome from trade negotiations with the United States.

The ROK is hoping to contain the effects of hefty US tariffs that could weigh on an export-reliant economy with major semiconductor, auto and steel industries.

Lee said tariff negotiations with the US had "not been easy", and he could not say if an agreement was possible in time for Washington's July 9 deadline when tough "reciprocal "import duties are set to kick in.

The ROK's top trade envoy Yeo Han-koo said on Thursday that Seoul wanted to ensure that it was not put at a comparative disadvantage as other major countries conduct last-minute trade negotiations with the US.

Lee, a liberal former human rights lawyer, said the alliance with the US was the cornerstone of his foreign policy, but pledged a pragmatic approach as the basis of a speedy effort to improve ties with China and Russia.

Peace with the Democratic People's Republic of Korea was not only a national security priority, but a crucial part of a "virtuous cycle of peace and economic growth", he said.

"Even if you're at war, you have to have diplomacy and dialogue. To completely cut off dialogue is truly foolish," Lee said regarding relations with Pyongyang.

Agencies Via Xinhua