President Joe Biden's nominee for deputy secretary of state highlighted the need Thursday to focus "even more" on deterrence against growing North Korean threats, noting Pyongyang continues to perfect its long-range weapons capabilities while shunning dialogue.

Kurt Campbell, currently the National Security Council coordinator for Indo-Pacific affairs, made the remarks during a Senate confirmation hearing as he responded to a question of whether he has any "creative" ideas to address the North Korean quandary.

"I am worried that North Korea in the current environment has decided that they are no longer interested in diplomacy with the United States," he said. "That means that we are going to have to focus even more on deterrence."

Campbell was apparently referring to last week's statement by Kim Yo-jong, the sister of North Korean leader Kim Jong-un. In the statement, she ruled out the possibility of the North resuming dialogue with the US, adding to tensions heightened by Pyongyang's satellite launch.

Kim's statement added to growing skepticism over the prospects of dialogue between the US and the North at a time when Washington is consumed heavily with a range of global challenges, including Russia's war in Ukraine and the war between Israel and the Hamas militant group.

Noting that the North Korean conundrum has "flummoxed" American diplomats for decades, Campbell said that the Biden administration has taken some "creative" and "inventive" approaches toward the North, such as offering vaccines during the height of COVID-19 and other kinds of engagements on humanitarian grounds.

"The last constructive diplomatic engagement that we had with North Korea was the aborted meeting in Vietnam between Kim Jong-un and Trump," he said. "Essentially since then, the North Koreans have rebuffed every effort that we have utilized to try to reach out to them."

He added, "We've had difficulty getting any takers even in addressing our letters or approaches to them."

The nominee also expressed concerns over growing military cooperation between the North and Russia as well as the North's advancing nuclear and missile capabilities.

"I am concerned that North Korea has taken very dangerous steps with respect to Russia, providing military equipment to Russia's campaign (against Ukraine)," he said. "I am also concerned that North Korea continues to perfect its long-range missile and nuclear capabilities in ways that are antithetical not only to the region but also to the US as well."

Asked to comment on the ongoing efforts to hold trilateral talks between South Korea, Japan and China, Campbell expressed confidence that Beijing will be "unsuccessful in building the kind of the bonds of trust" that the US has with the two East Asian allies.

Commenting on the relations between Seoul and Tokyo, Campbell pointed out the US' goal to see the two neighbors "put their animosity behind them to focus on the future" in every area, including energy, technology and security.

A thaw in relations between South Korea and Japan emerged after South Korean President Yoon Suk Yeol offered a solution in March to the long-running issue of Japan's wartime forced labor. Washington's efforts for trilateral cooperation with the two allies have since gathered steam.

"I do want to also just say it is in our interest to commend more publicly the risks and the courage that has been shown by Japan and South Korea," he said. "They need to recognize that we fully support at every possible level what they've done and we seek to strengthen it as it goes forward."

While noting the importance of America's role over the conflicts in the Middle East and Ukraine, Campbell emphasized his steadfast focus on the Indo-Pacific, where he said the US' long-term interests will play out over the remainder of this century. But he noted there are countries that are "testing us" in apparent reference to China and other potential adversaries.

"If confirmed, I will do everything possible ... to make sure that we are not tested, and that we stand ready to respond to any challenges to our power and to our allies in the Indo-Pacific more directly," he said.

Last month, Biden nominated him for the State Department's No. 2 post that has been left vacant since former Deputy Secretary Wendy Sherman retired in July.

Campbell has served as deputy assistant to the president and coordinator for the Indo-Pacific since January 2021. From 2009 to 2013, he worked as the assistant secretary of state for East Asian and Pacific affairs. (Yonhap)