STATE DEPARTMENT - Chief diplomats from the United States and South Korea said Friday that a complete denuclearization by North Korea requires robust verification, and that sanctions against Pyongyang would not be lifted unless it took concrete and further steps toward denuclearization.

U.S. Secretary of State Mike Pompeo’s first meeting with South Korea Foreign Minister Kang Kyung-wha in Washington comes just weeks before South Korean President Moon Jae-in’s planned visit to the White House, and the highly anticipated summit between President Donald Trump and North Korea leader Kim Jong Un.

Trump had announced he would meet with Kim in Singapore on June 12, two days before the U.S. leader’s 72nd birthday.

“The United States and the Republic of Korea are committed to achieving the permanent, verifiable and irreversible denuclearization of the Korean Peninsula,” Pompeo said during the joint press conference.

“We're not talking about sanctions relief at this point,” Kang said. “We’re very clear that the sanctions remain in place until and unless we see visible meaningful action taken by North Korea on the denuclearization track.”

South Korean Foreign Minister Kang Kyung-wha, left South Korean Foreign Minister Kang Kyung-wha, left, and Secretary of State Mike Pompeo arrive for press conference at the State Department, May 11, 2018, in Washington. South Korean Foreign Minister Kang Kyung-wha, left, and Secretary of State Mike Pompeo arrive for press conference at the State Department, May 11, 2018, in Washington.

U.S. officials had called for North Korea to take bold actions and concrete steps toward denuclearization. By doing so, they said, Washington is “prepared to work with Pyongyang to achieve prosperity.”

However, experts told VOA there is a gap between the United States and North Korea regarding the steps toward denuclearization, with North Korea continues to press for a phased and incremental approach.

“If the two sides can agree on a path forward, the United States could likely offer some combination of security guarantees, economic incentives and sanctions relief, and a path to normalization of relations,” former State Department official Mintaro Oba said.

President Donald Trump speaks as he stands with To President Donald Trump speaks as he stands with Tony Kim, second left, Kim Dong Chul, center right, and Kim Hak Song, right, three Americans detained in North Korea for more than a year, after they arrived at Andrews Air Force Base in Md., May 10, 2018. President Donald Trump speaks as he stands with Tony Kim, second left, Kim Dong Chul, center right, and Kim Hak Song, right, three Americans detained in North Korea for more than a year, after they arrived at Andrews Air Force Base in Md., May 10, 2018.

The top U.S. diplomat said the release of three American detainees set the conditions for a successful summit between the U.S. and North Korea.

Early Thursday, Trump personally welcomed three freed Americans returning home from North Korea, declaring, “We’re starting off on a new footing”with Pyongyang.

“We wish these Americans and their families the best, as they reconnect after a very difficult time apart,” Pompeo said.

Trump is set to welcome South Korea President Moon May 22 at the White House, the first meeting between the two since the April 27 inter-Korean summit between Moon and Kim.

The Panmunjom Declaration for Peace, Prosperity and Unification was signed by South and North Korean leaders, which laid out a peaceful path forward.

“We can’t overstate the pivotal role President Moon has played in getting us where we are today. South Korean diplomacy has turned fire and fury into summits and stability,” Oba told VOA, referring to Trump's previously tough talks against Pyongyang.