The United States will shift a majority of its warships to the Asia-Pacific region by 2020, Defense Secretary Leon Panetta said June 2, giving the first details of a new U.S. military strategy.

Fleshing out details of a strategic shift to Asia announced in January, Panetta said the United States would maintain six aircraft carriers in the region over the long run and rebalance its fleet so that 60 percent of its other warships would be assigned to the Pacific by 2020, compared to 50 percent now.

The U.S. defense secretary, speaking at an annual security forum in Singapore, also sought to dispel the notion that the shift, after more than a decade of war in Afghanistan and Iraq, was designed to contain China’s emergence as a global power.

He acknowledged differences between the world’s two largest economies on a range of issues, including the South China Sea.

“We’re not naive about the relationship and neither is China,” Panetta told the Shangri-La Dialogue attended by senior civilian and military leaders from about 30 Asia-Pacific nations.

“We also both understand that there really is no other alternative but for both of us to engage and to improve our communications and to improve our (military-to-military) relationships,” he said. “That’s the kind of mature relationship that we ultimately have to have with China.”

Some Chinese officials have been critical of the U.S. shift of military emphasis to Asia, seeing it as an attempt to fence in the country and frustrate Beijing’s territorial claims.

China has downgraded its representation to the Shangri-La Dialogue from last year, when Defence Minister Liang Guanglie attended and met then-U.S. Defense Secretary Robert Gates. This year the Chinese military was represented by the vice president of the Academy of Military Sciences.

Panetta, by contrast, was accompanied by Army Gen. Martin Dempsey, the U.S. military’s top officer as chairman of the Joint Chiefs of Staff, and Navy Adm. Samuel Locklear, the head of the U.S. Pacific Command.