U.S. Secretary of State John Kerry's offer of dialogue with North Korea reflects South Korean President Park Geun-hye's vision for relations with the communist neighbor, his department said Friday.

After talks with South Korean Foreign Minister Yun Byung-se in Seoul, Kerry told reporters that Washington hopes for negotiations with North Korea.

"The president and the secretary have been clear that we're open to engagement. But I think really in this context he was referring to President Park's positive vision," Patrick Ventrell, the deputy spokesman for the State Department said at a press briefing in Washington.

He was explaining Kerry's intention behind his remarks in Seoul, the first stop on his Northeast Asia tour.

Kerry urged North Korea to stop an apparent move toward an intermediate-range missile launch, saying Washington's preference would be to talk with Pyongyang.

On the preconditions for the resumption of talks, the secretary said the North should be prepared to live up to international obligations and show seriousness about denuclearization.

Earlier, the South Korean leader said Seoul will try to build mutual trust with Pyongyang for dialogue and co-prosperity.

Meanwhile, the White House played down a report by the Pentagon's intelligence arm that North Korea appears to have learned a technology to miniaturize nuclear bombs for delivery by ballistic missiles.

"I want to be clear that North Korea has not demonstrated the capability to deploy a nuclear-armed missile," said White House Press Secretary Jay Carney, briefing reporters separately.

In a congressional hearing Thursday, Rep. Doug Lamborn (R-CO) disclosed an unclassified section of a report by the Defense Intelligence Agency in which it said "with moderate confidence" Pyongyang has nuclear weapons capable of delivery by ballistic missiles, although the reliability will be low.

North Korea has conducted three known nuclear tests and carried out several ballistic missile launches. The world has been paying keen attention to whether it has a nuclear warhead.

George Little, the spokesman for the Pentagon, said it's early to conclude Pyongyang has mastered the sophisticated technology.

"While I cannot speak to all the details of a report that is classified in its entirety, it would be inaccurate to suggest that the North Korean regime has fully tested, developed or demonstrated the kinds of nuclear capabilities referenced in the passage," he said.

(Yonhap News)