The Asia "pivot", the United States' strategic shift in focus to the world's most populous continent, marks a new phase - with opportunities outweighing challenges - as regional powers China, Japan and the Republic of Korea undergo leadership changes, President Barack Obama's national-security adviser said on Monday.

Outlining China as a major "pillar" of the US rebalancing on Asia policy, Thomas Donilon said the world's two biggest economies should continue building a "constructive relationship" and pointed to "substantial progress" made in the four years since Obama took office.

"The president places great importance on this relationship because there are few diplomatic, economic or security challenges in the world that can be addressed without China at the table and without a broad, productive and constructive relationship between our countries," Donilon told an audience at the Asia Society in New York.

In a speech on Asia policy during Obama's second term, Donilon said the administration is well positioned to build on existing relationships with the new leadership headed by Xi Jinping.

"Taken together, China's leadership transition and the president's re-election mark a new phase in US-China relations - with new opportunities," said Donilon, who has served as Obama's top national-security aide since October 2010.

The US and China, he said, should focus on improving the quality and quantity of cooperation while promoting "healthy economic competition".

The "pivot" was among the major foreign-policy initiatives of Obama's first term, highlighting a US strategy to assert military might in the Asia-Pacific region. Some experts see the policy as a means of balancing China's influence there.

The Obama aide, who served as assistant secretary of state for public affairs under President Bill Clinton, said he disagreed with the view of some that China's rise inevitably creates conflict between the two countries. The United States welcomes a "peaceful, prosperous" China, Donilon said in his speech.

"We do not want our relationship to become defined by rivalry and confrontation," he said. "And I disagree with the premise put forward by some historians and theorists that a rising power and an established power are somehow destined for conflict."

Ian Bremmer, president of the Eurasia Group, a political-risk-assessment firm, told CNN in January that the emergence of China on the world stage has "enormous implications" for both economic and political conflict.

"Here you have a situation for many decades where Americans felt that China's rise was in their interest - already Japan understands that China's rise is not in its interest, it's a bad thing," Bremmer said. "Increasingly, the US is very, very conflicted."

Donilon, however, said on Monday that such a result can be avoided if both sides manage their relationship wisely.

"There is nothing preordained about such an outcome; it is not a law of physics but a series of choices by leaders that lead to great-power confrontation," he said.

"But it falls to both sides - the United States and China - to build a new model of relations between an existing power and an emerging one. Xi Jinping and President Obama have both endorsed this goal.

"To build this new model, we must keep improving our channels of communication and demonstrate practical cooperation on issues that matter to both sides."

While looking ahead to opportunities, the White House adviser also urged the nations to tackle a few challenges, including deepening their military interaction and strengthening economic ties.

"A deeper US-China military-to-military dialogue is central to addressing many of the sources of insecurity and potential competition between us," Donilon said. "We need open and reliable channels to address perceptions and tensions about our respective activities in the short term and about our long-term presence and posture in the western Pacific."

He also cited cyber security as a "growing challenge" the two countries must address.

"Economies as large as the United States and China have a tremendous shared stake in ensuring that the Internet remains open, interoperable, secure, reliable and stable," he said. "Both countries face risks when it comes to protecting personal data and communications, financial transactions, critical infrastructure, or the intellectual property and trade secrets that are so vital to innovation and economic growth."

In February, private US Internet-security firm Mandiant issued a report accusing a secret Chinese military unit in Shanghai of being behind years of cyberattacks against US companies.

China has denied the accusation.

China's Foreign Minister Yang Jiechi on Saturday said that "cyberspace needs rules and cooperation, not war", and he urged the US to end "irresponsible rebuke or criticism" of China.

"The international community is closely interconnected on the Internet, therefore cyberspace needs rules and cooperation, not war," Yang told a news conference on the sidelines of the NPC session in Beijing. "We oppose turning cyberspace into another battlefield, or to capitalize on virtual reality to interfere in other countries' internal affairs."

yuweizhang@chinadailyusa.com