WASHINGTON (Kyodo) -- The United States aims to denuclearize North Korea by the end of President Donald Trump's first term in January 2021, a senior State Department official said Thursday.
Denuclearization involves removing nuclear warheads and fissile material, destroying intercontinental ballistic missiles, and permanently freezing any other weapons of mass destruction programs, the official told reporters.
"In our view, it is still doable within the president's first term, and that's what we're pushing very hard with our North Korean interlocutors to achieve," the official said, speaking on condition of anonymity.
Separately, White House national security adviser John Bolton said Trump is open to holding further talks with North Korean leader Kim Jong Un over denuclearization despite the breakdown of their second meeting last week.
"(The) president's obviously open to talking again," Bolton told Fox News. "We'll see when that might be scheduled or how it would work out. But he thinks the deal is there if North Korea is prepared to look at the big picture."
The comments from the official and Bolton came amid reports that Pyongyang has rebuilt a missile engine testing site in the country's northwest to normal operating status in an apparent challenge to the Trump administration's push for the final, fully verified denuclearization of North Korea.
Referring to the Feb. 27-28 summit in Vietnam's capital Hanoi, Bolton said Trump pushed for "a big deal that would give North Korea a bright future but which results in complete denuclearization."
But North Korea apparently sought to "give up as little of their nuclear, biological and chemical weapons and ballistic missile programs as they could in exchange for very broad sanctions relief," according to Bolton.
"(The) president wasn't buying it," he said. "Kim Jong Un had presented a formula that the North Koreans have tried before. It was unsatisfactory."
According to the senior State Department official, Trump urged Kim in Hanoi to completely eliminate Pyongyang's weapons of mass destruction program while laying out "an expansive vision for a brighter future that would be available for North Korea."
"Ultimately at the conclusion of the summit, the ball was in North Korea's court," the official said. "And it is going to be up to the North Koreans, to some extent, to decide to engage on meeting some of the expectations that are out there on denuclearization."
Citing satellite imagery taken the previous day, 38 North, a U.S. group that monitors North Korea, said Thursday that construction to rebuild the launch pad and engine test stand at the Sohae Satellite Launching Station in Tongchang-ri that began before the Hanoi summit has continued "at a rapid pace."
"Given that construction plus activity at other areas of the site, Sohae appears to have returned to normal operational status," it said.
Asked if he was disappointed by the moves at Sohae, Trump said, "A little disappointed. A little bit."
"We'll see. We'll let you know in about a year," Trump told reporters at the White House, without elaborating.
The State Department official said the United States will continue to call for the admission of American inspectors to Sohae so it can verify the permanent dismantlement of the facility.
Releasing a similar assessment, the Center for Strategic and International Studies, a Washington think tank, said the rebuilding activities "constitute an affront to the president's diplomatic strategy as well as demonstrate North Korean pique at Trump's refusal to lift economic sanctions during the meetings in Hanoi."
The activities amount to a snapback from Pyongyang's claimed dismantlement of Sohae following the first-ever U.S.-North Korea summit in June last year in Singapore, where Kim pledged to work toward "complete" denuclearization of the Korean Peninsula.