Washington, February 3 (RHC)-- The U.S. Defense Department will seek more than $13 billion over the next five years to fund the development and production of new submarines to carry nuclear ballistic missiles.

The U.S. Navy would spend over $4 billion on research and development of the new submarines, plus over $9 billion in procurement funding, according to Reuters, citing sources familiar with the plans.

The five-year budget plan also shifts the Navy's strategy for a new carrier-based unmanned drone to focus more on intelligence-gathering and refueling than combat strike missions, said the sources, who were not authorized to discuss it publicly before the budget's release.

The Pentagon's plan will also emphasize the need to fund all three parts of the US strategic deterrent known as "triad" which involves the replacement of the Ohio-class submarines that carry nuclear weapons, a new Air Force bomber and new nuclear-armed intercontinental ballistic missiles, said one of the sources.

On Tuesday, U.S. Defense Secretary Ashton Carter said the Pentagon would spend $8.1 billion on undersea warfare in fiscal 2017 and more than $40 billion in the next five years.

Carter, speaking to the Economic Club of Washington, said the initiative is aimed at giving the United States the most lethal undersea and anti-submarine force in the world, funding nine Virginia-class submarines built by General Dynamics and Huntington Ingalls Industries.