Seoul, South Korea ? North Korea expressed willingness today to resolve concerns over its nuclear weapons program through dialogue, South Korean officials said. But the United States has cast North Korea’s nuclear program as a non-negotiable issue, saying it must be dismantled immediately.

Kim Yong Nam, the North’s ceremonial head of state, made the remarks in a meeting with South Korean delegates in Pyongyang, the North’s capital, according to South Korean pool reports.

Kim’s remarks were the North’s first official response to a U.S. announcement last week that the communist country had admitted to having a nuclear weapons program in violation of international agreements.

“We consider the recent situation seriously,” pool reports quoted Kim as telling the chief South Korean delegate, Jeong Se-hyun. “If the United States is willing to withdraw its hostile policy toward the North, the North also is ready to resolve security concerns through dialogue.”

The remarks were reported by South Korean journalists sent to cover the three-day inter-Korean talks, which opened on Sunday. No foreign reporters were allowed to cover the talks.

The talks in Pyongyang, the eighth since a historic inter-Korean summit in 2000, were meant to discuss inter-Korean reconciliation, but the nuclear issue took priority.

U.S. Assistant Secretary of State James Kelly earlier this month met Kim Yong Nam when he visited Pyongyang. During Kelly’s trip, North Korean officials admitted that they have a uranium-enriching program to make nuclear weapons.

The North’s admission violates a 1994 agreement it signed with the United States, promising to abandon its suspected nuclear weapons program in return for construction of two modern, light-water reactors and 500,000 tons of fuel oil a year until the reactors are completed.

South Korean Unification Minister Jeong Se-hyun, left, and his North Korean counterpart, Kim Ryong Sung, center, are led by a North Korean guide during a visit to the tomb of Dongmyung King in Pyongyang, North Korea. The ministers on Sunday discussed current bilateral issues, including North Korea's nuclear weapons program.

In talks with Kelly, North Korea said it considered the 1994 agreement invalid because the reactors were not expected to be completed by 2003 as promised.

U.S. Secretary of State Colin Powell said Sunday in Washington that the U.S. government considers the agreement effectively dead because of the North’s secret nuclear weapons development.

North Korea “blamed us for their actions and then said they considered that agreement nullified,” Powell said on NBC television. “When you have an agreement between two parties, and one says it’s nullified, then it’s hard to see what you do with such an agreement.”

Powell said the United States, together with allies and Asian regional powers, will muster “maximum pressure” on North Korea to persuade it to give up its nuclear weapons program.

U.S. officials have said there were aspects of the agreement that the United States wants to preserve, including a U.N.-monitored freeze on North Korea’s earlier nuclear program.

The Koreas were divided in 1945. About 37,000 U.S. troops are stationed in South Korea, a legacy of the 1950-53 Korean War.