In this undated photo provided on Sunday, May 24, 2020, by the North Korean government, North Korean leader Kim Jong-un speaks during a meeting of the Seventh Central Military Commission of the Workers' Party of Korea in North Korea. AP

U.S. National Security Adviser Robert O'Brien renewed calls Sunday for North Korea to give up its nuclear program if it wants to have a "great economy," after North Korean leader Kim Jong-un held a key party meeting to discuss bolstering nuclear deterrence.

In his first public appearance in about three weeks, Kim presided over a session of the Workers' Party's Central Military Commission to discuss "new policies for further increasing the nuclear war deterrence," the North's official Korean Central News Agency reported Sunday.

The North's first mention of "nuclear war deterrence" since early 2018 came amid an impasse in nuclear talks between Washington and Pyongyang, and its struggle to improve its economy crippled by global sanctions and a pandemic-driven plunge in trade with China.

"We've managed to avoid a conflict with North Korea over the last 3 1/2 years. The president has engaged in some excellent personal diplomacy with Kim Jong-un," O'Brien said in an interview with CBS News' "Face the Nation."

"But ultimately, the North Koreans, if they want to reenter the world, if they want to have a great economy, we hope they do, they are going to have to give up their nuclear program," the official added.