SAN DIEGO (TIP): Defence secretary Ash Carter said on sept 29 the US will “sharpen our military edge” in Asia and the Pacific in order to remain a dominant power in a region feeling the effects of China‘s rising military might.

Carter made the pledge in a speech aboard the aircraft carrier USS Carl Vinson in port in San Diego.

The Pentagon chief described what he called the next phase of a US pivot to Asia — a rebalancing of American security commitments after years of heavy focus on the Middle East.

His speech, aimed at reassuring allies unsettled by China’s behavior in the South China Sea, came three days after he made remarks at a nuclear missile base in North Dakota about rebuilding the nuclear force. Those comments prompted a strong reaction from the Russian foreign ministry, which issued a statement saying it had interpreted Carter’s statement as a declared intention to lower the threshold for using nuclear weapons.

Carter said the Pentagon will make its attack submarines more lethal and spend more to build undersea drones that can operate in shallower waters where submarines cannot.

“The United States will continue to sharpen our military edge so we remain the most powerful military in the region and the security partner of choice,” he said. He added, “We’re going to have a few surprises as well,” describing them only as “leap-ahead investments.”

With a broad complaint that China is “sometimes behaving aggressively,” Carter alluded to Beijing’s building of artificial islands in disputed areas of the South China Sea.

“Beijing sometimes appears to want to pick and choose which principles it wants to benefit from and which it prefers to try to undercut,” he said. “For example, the universal right to freedom of navigation that allows China’s ships and aircraft to transit safely and peacefully is the same right that Beijing criticizes other countries for exercising in the region. But principles are not like that. They apply to everyone, and every nation, equally.”

Carter’s speech was meant to set the scene for a meeting on Friday in Hawaii with his counterparts from the 10 member countries of the Association of Southeast Asian Nations, or ASEAN. The association focuses mainly on trade issues, but in recent years, with US encouragement, has sought to engage in a range of defence and military issues. The US is not a member of the organization but has sought to use it as a forum for further developing security partnerships amid regional concern about China’s military buildup.

On Carter’s flight from San Diego to Hawaii later on Sept 29, a senior defence official aboard the plane told reporters that Carter expects to hear concerns from some Southeast Asian ministers, including those from Singapore, Indonesia and the Philippines, about the threat they perceive from an expected return of extremists who have been fighting for the Islamic State group in Syria and Iraq.

The official, who spoke on condition of anonymity under ground rules set by the Pentagon, said “hundreds” of IS fighters already have returned to Southeast Asia from Syria and Iraq and said up to 1,000 more may return as the Islamic State group faces increased military pressure.

Carter has described Pentagon efforts to execute a “pivot” to Asia by shifting, or rebalancing, US forces and attention toward the Asia-Pacific region after a decade and a half of Mideast-focused strategies and operations.

In April, he said he was putting “the best people and platforms forward to the Asia-Pacific” by increasing the number of US military personnel in the region and by sending and stationing advanced weapons system there. He said that includes F-22 and F-35 stealth fighter jets, P-8 Poseidon maritime surveillance aircraft, continuous deployments of B-2 and B-52 strategic bombers and the newest surface warfare ships like the amphibious assault ship USS America.

Among the Asia problems that have arisen for the Pentagon since Carter last met with the region’s defence ministers is a sudden and steep deterioration in relations with the Philippines.

When Carter visited the Philippines in April, he praised the strength of the partnership. He said his visit had inaugurated “a major new era in a longstanding alliance.” He was referring to the US-Philippines Enhanced defence Cooperation Agreement. “I’m proud to say this alliance is as close as it’s been in years.”