WASHINGTON -- US Secretary of Homeland Security John Kelly said Sunday that North Korea could perfect its capabilities to send a nuclear-tipped missile to the continental US during President Donald Trump's first term.

"Clearly there are countries on the planet that have a lot of nuclear weapons that would overwhelm any defense that we would deploy, Russia, as an example. But the minute North Korea gets a missile that could reach the United States, puts a weapon on that missile, nuclear weapon, the instant that happens, this country is at grave risk," Kelly said on CNN.


Asked how far away that possibility is, he said, "I think Mr. Trump will be dealing with this in real terms before he starts his second term."

Kelly declined to comment on whether the US military could shoot down a missile from the North.

Concerns about North Korean nuclear and missile threats have deepened in the U.S. since Kim said in his New Year's Day address that the country is ready to test-fire an intercontinental ballistic missile apparently capable of reaching the US.

Former US Ambassador to the UN John Bolton also said the North could soon harm the US "directly."

"The North Koreans, this very erratic, unstable regime, may soon have the capability to harm us directly," Bolton said on New York's AM 970 radio. "The real objective of the Trump administration has to be to convince China that it's in their best interest to find a way to reunify the Korean Peninsula as peacefully as possible."

He also warned that the North is likely working on perfecting its submarine capabilities, making it possible for the country to send strategic submarines to the US west coast.

"If they can achieve that capability, they could put nuclear weapons on submarines that could get much closer to the United States," Bolton said. That might go undetected in the vast Pacific Ocean."

Bolton also said it's important to keep all military options on the table.

"If our main purpose is to prevent North Korea from having nuclear weapons, I think the only long-term assurance we have that that is achievable is by reunifying the two Koreas. Faced with the choice of using military force or trying to get reunification -- I think we always have to keep force on the table -- but if there's any diplomatic option left, it is pushing China towards accepting reunification," he said. (Yonhap)