TOKYO -- The U.S. Navy will use the combined power of its Pacific Fleet -- the 7th Fleet and the 3rd Fleet -- to counter rising uncertainty in Asia, a senior naval officer told the Nikkei Asian Review on Tuesday.

"This is real. The commitment of the 3rd Fleet [operating] forward is real," said Adm. Scott Swift, the four-star commander of the Pacific Fleet in an exclusive interview during his visit to Japan. The 7th Fleet, based in Yokosuka, and the 3rd Fleet, based in the U.S. city of San Diego, are separated by the international date line near Hawaii. The 3rd Fleet is mainly tasked with protecting the U.S. homeland, while the 7th Fleet is responsible for everything between Hawaii and the India-Pakistan border, including the hotly contested South China Sea.

"I have a lack of understanding of why there is such allegiance to the international date line. This is a blurring of the demarcation," Swift said, arguing the Navy should utilize the "total combined power" of the 140,000 sailors, the over 200 ships and the 1,200 aircraft that make up the Pacific Fleet.

His words come just days after a Chinese frigate entered the "contiguous zone" near the Japanese-administered Senkaku Islands, in the East China Sea. It was the first time a vessel belonging to the People's Liberation Army has come so close to the islands. Swift said he sees a "common theme" occurring in both the South China Sea and the East China Sea, where "a context of uncertainty and angst in the region has brought about a lack of transparency."

He said that the U.S. and China have put mechanisms in place to generate dialogue between the two militaries, but that there is more to be done in terms of enhancing mutual understanding. "Is there a signal being sent? Have things changed? We find ourselves, once again, in this wait and see because right now dialogue is not leading to more clarity," he said.

Swift also voiced worries about recent Chinese statements regarding the South China Sea. "I was struck by comments that have been made, with claims outside of what the Chinese refer to as the Nine-Dash Line. There is a new reference being made -- that I hear about traditional fishing grounds. That has raised concerns," he said.

Putting it together

The increased integration of the 7th and 3rd Fleets should mean more 3rd Fleet vessels operating in the western Pacific, which is traditionally the 7th Fleet's area. One such operation is the deployment of the Pacific Surface Action Group, under which the destroyers USS Spruance, USS Decatur and USS Momsen have embarked on a seven-month tour of Asia.

The ships will conduct a broad range of operations in the 7th Fleet's area, while remaining under the operational control of 3rd Fleet commander Vice Adm. Nora Tyson.

Swift has been sending Tyson to events in the western Pacific in recent months to signal the increased involvement of the 3rd Fleet in the region. "Adm. Tyson represented me at the Japanese International Fleet Review, here. She represented me at conferences and leadership events in New Zealand and Australia. She officiated over the change of command of the John C Stennis strike group in Singapore," Swift said.

"This is a recognition that we will continue to operate around the world in accordance with international norms and laws, and in a maritime perspective in accordance with UNCLOS [the United Nations Convention on the Law of the Sea], with the total combined power of the Pacific Fleet, which includes both 7th and 3rd Fleet."