Nuclear-armed North Korea has a ballistic missile that could hit the United States, the leading lawmaker on the US House of Representatives intelligence committee warned Sunday.
Congressman Mike Rogers also raised concern that North Korea's young leader Kim Jong-Un is trying to prove himself to his military and that Washington could not be sure of his "stability."
"They certainly have a ballistic missile that can reach US shores," Rogers told the CNN news network, without specifying whether he was referring to the more exposed US states of Alaska and Hawaii or to America's west coast.
"You have a 28-year-old leader who is trying to prove himself to the military, and the military is eager to have a saber rattling for their own self-interest, and the combination of that is proving to be very, very deadly."
North Korea has tested missiles that could strike South Korea or Japan but has yet to demonstrate it has the capability to fire long-range missiles that could reach the continental United States.
It is also not clear how close North Korea is to being able to convert one of the nuclear devices that it has tested to function as a missile warhead.
On Friday, the United States said it would beef up its defenses against a possible North Korean missile strike a week after Pyongyang threatened a "pre-emptive" nuclear attack against its arch enemy.
Defense Secretary Chuck Hagel said 14 more interceptors would be stationed in Alaska by 2017, increasing by almost half the number already deployed along the California and Alaska coastlines.
Pyongyang has threatened to unleash a second Korean War -- backed by nuclear weapons -- in response to UN sanctions imposed after its third atomic test last month and to joint South Korea-US military maneuvers.
"This is something that we have to take seriously, and you can see that they're looking for some provocations, not just along the border, but there's some islands that they're interested in," Rogers said.
Rogers acknowledged the United States knew more about Kim's father, Kim Jong-Il, than it does about the country's current head.
"We just don't know the stability" of the 28-year-old, Rogers said.