Groton - The Navy plans to keep fewer submarines in Groton as the military shifts its focus toward Asia and sends its newest, most capable ships and aircraft to the western Pacific, the Navy's top admiral said Tuesday.

By 2020, the Naval Submarine Base is expected to have two squadrons with six attack submarines per squadron, instead of the 16 submarines it has today.

The naval station in Norfolk, Va., will have fewer submarines in the future, too, while the base in Kings Bay, Ga., will not be affected by the rebalancing since ballistic-missile submarines need to remain there as a strategic deterrent, Adm. Jonathan W. Greenert said.

Greenert was in town for a classified conference on undersea warfare technology.

"We're pretty well set up to execute this strategy, and now we have to evolve and make that rebalance that is called for," Greenert, the chief of naval operations, said in an interview at the base.

There will not be any great departure of submarines and crews. Rather, submarines that retire in the East will not always be replaced with new boats, while submarines in the West will be, Greenert said. The number of submarines in the fleet will decline overall as the aging Los Angeles-class attack subs retire more quickly than the Virginia-class submarines are built.

Even with the changes, Greenert said, the Navy needs three submarine bases along the East Coast. The Norfolk naval station does not have the capacity to support the submarines from Groton, and it would be too expensive to relocate the submarine school from the base, he added.

The three locations are "a good balance," Greenert said, and he does not intend to "move submarines en masse" out of the Groton area.

The strategic documents clearly state the Navy has to dominate the undersea domain, to "own it," Greenert said.

"To do that, the centerpiece of it is the submarine, make no mistake," he said, adding that various other platforms and payloads will also play important roles as parts of the network.

The Navy's forces overall are evenly distributed between the Atlantic and the Pacific, while the distribution of submarines is already closer to 60 percent in the Pacific.

In the future, 60 percent of the forces, including aircraft carriers, cruisers, destroyers, littoral combat ships and submarines, will be based on the West Coast and in the Pacific. That equates to 10 more ships operating in the western Pacific in 2020, with more ships based in Japan and Guam instead of rotating between the region and the United States.

The Navy wants to establish or re-establish relationships with numerous allies throughout Asia, Greenert said.

While some have said the strategy, announced in January, is a way to contain China's growing military power, Greenert dismissed that idea as an oversimplification. China, the major player in the region, put its first aircraft carrier into service on Tuesday.

"There are many things that could tend to be an outcome. You could say, 'Well, you did all this, this came out of that,' and that would be a conclusion someone draws," he said, adding later, "That's not the intent directly. It is, like I said, to establish those relationships and re-nurture them."

Greenert said the strategy is not just about having the right number of ships in the region. It is also about having the right mix of capabilities, both in vessels and aircraft, as well as having the proper training for those who will deploy there and more complex exercises to engage allies.

Officials in Singapore recently agreed to host up to four of the Navy's littoral combat ships. The Navy plans to send the new P-8A Poseidon aircraft to Okinawa and unmanned aircraft to Guam when they come online, as well as send new Virginia-class submarines and destroyers to the region.

The Navy's presence in the Caribbean, Central and South America and Africa will slightly shrink. But the Navy could use other capabilities in some areas, including unmanned systems, and work with allies who have professional, capable submarine forces, Greenert said.

The plans for rebalancing are feasible unless sequestration occurs, he added.

The $1.2 trillion in automatic spending cuts known as sequestration will take effect Jan. 1 if Congress does not act to prevent it. The Navy's shipbuilding and conversion funding would be cut by $2.14 billion in 2013 under sequestration, according to the Office of Management and Budget.

That would render the strategy "un-executable," Greenert said.