The U.S. Pacific Fleet commander said he plans to expand the role of the U.S. 3rd Fleet commander and her staff in the Asia-Pacific region.

The Pacific Fleet consists of the 3rd Fleet headquartered in San Diego and the 7th Fleet headquartered in Yokosuka, Japan. For decades, the 7th Fleet has taken command of 3rd Fleet ships when they crossed the international dateline.

But Adm. Scott Swift said Tuesday he plans to have 3rd Fleet commander Vice Adm. Nora Tyson and her staff maintain operational control of some of these ships when they travel west. For example, he says the 3rd Fleet could lead the Navy's response to a tsunami while the 7th Fleet focuses on Japanese earthquake relief.

The Navy hasn't been taking full advantage of 3rd Fleet capacity and capability, Swift said.

The first sailors to deploy under this arrangement are scheduled to leave Pearl Harbor on Wednesday. Their ships — the USS Momsen, based in Everett, Washington, and the USS Decatur and USS Spruance based in San Diego, California — are deploying together as a surface action group.

The 3rd Fleet leaders can help out the 7th Fleet, which is already busy in the Asia-Pacific region, Swift said.

"The future is very unpredictable. If we hit that capacity point, we don't want to find ourselves for the first time asking the question, well let's see what we can do with 3rd Fleet. We need to start those actions now," Swift told reporters after speaking to sailors on the Momsen.

Swift said Tyson has already taken on more duties in the region, for example representing him at a review of Japanese naval forces in October. The 7th Fleet commander was unable to be there because he was supporting an exercise in South Korea.

Tyson also recently met with Australian and New Zealand navy leaders during visits to those countries. Swift said he plans to have the 3rd Fleet take an active role in Talisman Sabre, a U.S.-Australian exercise that takes place every other year.

Swift said the shift won't mean more 3rd Fleet ships will be deploying to the region. The number of ships deploying should stay the same.

Capt. Charles Johnson, the commodore of the three-destroyer surface action group leaving Hawaii on Wednesday, said sailors on the ships won't notice any difference in the deployment with the 3rd Fleet maintaining operational control.