WASHINGTON -- US Deputy Secretary of State Stephen Biegun stressed the need for a mixture of "top-down" and "bottom-up" approaches to rid North Korea of its nuclear ambition in a meeting with a group of visiting South Korean lawmakers on Tuesday.

The top US negotiator in talks with North Korea also promised efforts to make sure his experience and lessons from dealing with the communist state will be transferred to the next US administration, according to the South Korean lawmakers, led by Rep. Song Young-gil of the ruling Democratic Party.

Their trip came after Democratic candidate Joe Biden was declared the winner of the Nov. 3 presidential election. Biden has been critical of President Donald Trump's top-down or summit diplomacy with North Korean leader Kim Jong-un.

"Deputy State Secretary Biegun said there have been difficulties in negotiating with North Korea since the end of the Hanoi summit, but that he still maintains hope and conviction that they can resolve the North Korean nuclear issue," the lawmakers said in a press release.

Song said he stressed the need to find a balance between top-down and bottom-up diplomatic steps in dealing with North Korea, and Biegun agreed on the need to use both approaches to have them complement each other, according to Song.

Trump held three meetings with the North's leader, but negotiations between the two countries have stalled since their second summit in Hanoi in February 2019 ended without a deal. They first met in Singapore in June 2018.

Song said he underscored the significance of the Trump-Kim summits as a "significant first step" that lured the reclusive North out from its long isolation.

"We hope the next US administration will continue such efforts ... so both South Korea and the United States, regardless of who has power in the countries, will continue to spearhead the development of relations between South, North Korea and the United States," Song told Biegun, according to the press release.

The South Korean lawmakers arrived here Sunday for talks with their US counterparts and officials from the US government and think tanks, including those close to President-elect Biden. (Yonhap)