Missiles test-fired by North Korea this week are "a quantum leap forward" from its previous weapons, the commander of the US military in South Korea said.
Speaking before the US House Armed Services Committee in Washington, Gen B. B. Bell said North Korea was also moving ahead with the development of longer-range ballistic missiles that could hit Alaska and targets in the continental United States.
North Korea's testing of two short-range missiles on Wednesday came during a stalemate in six-country talks aimed at ending its nuclear weapons programmes.
Pyongyang says it has nuclear weapons, but proliferation experts have questioned its ability to mount them on missiles.
"[They] are, in fact, a quantum leap forward from the kind of missiles that they have produced in the past," Gen Bell told the hearing, referring to the short-range missiles tested this week.
The missiles were boosted by solid fuel, rather than liquid fuel, providing greater reliability, mobility and precision, he said.
North Korea test-fired a similar missile in May last year. "They are routinely testing these," Gen Bell added.
A senior Bush administration official said the missiles tested this week did not leave North Korean territory.
South Korean daily JoongAng Ilbocited a government source saying North Korea fired the two missiles from its east coast and they probably dropped into the sea about 60 miles away.
