The United States will retire its sea-based nuclear Tomahawk missiles within a few years, believing it has other ways to defend Northeast Asia, a Pentagon official said Wednesday.

The elimination of the missile -- supported in the past by some policymakers in Japan and South Korea -- was part of a policy shift announced Tuesday by President Barack Obama's administration to reduce the role of nuclear weapons.

"The timeline for its retirement will be over the next two to three years," James Miller, the principal deputy undersecretary of defense for policy, told a news conference.

He said that the United States had held "extensive consultations" with US allies including Japan and South Korea about the decision to retire the nuclear Tomahawk, known in military jargon as the TLAM-N.

"We reached a point of mutual confidence that the TLAM-N was a redundant system not necessary for effective, extended deterrence for Northeast Asia," Miller said.

He said that the United States had other nuclear-capable systems including intercontinental ballistic missiles and submarine-launches ballistic missiles.

"If we think about systems that are potentially forward-deployable, they also include our tactical aircraft and they include our heavy bombers as well," Miller said.

An experts' report mandated by Congress had last year recommended the continued deployment of the nuclear Tomahawk, noting that US allies in Asia were part of nuclear planning.

"It has become clear to us that some US allies in Asia would be very concerned by TLAM-N retirement," said the Congressional Commission on the Strategic Posture of the United States.

But the Tomahawk nuclear missiles have also been a source of friction with Japan.

Japan's left-leaning government which took office last year commissioned a study which found that US forces had a secret pact with Tokyo to bring the nuclear weapons into the country, despite Japan's official non-nuclear stance.