Two new key members of US President Barack Obama's Cabinet may create an opportunity for improving Sino-US ties in Obama's second four-year term, analysts said.

Confirmation hearings for Senator John Kerry, nominated for secretary of state, and former senator Chuck Hagel, nominated for secretary of defense, are expected to start in the coming weeks.

Both Kerry and Hagel are senior politicians with a practical and moderate style, said Tao Wenzhao, an expert on US studies at the Chinese Academy of Social Sciences.

"Their nominations show that Obama will take a more cautious approach in foreign and defense policy in his second term," Tao said.

Both Kerry and Hagel are Vietnam War veterans known for their cautious attitudes on the use of US military forces abroad.

Time magazine even called Hagel "a different kind of defense secretary" and said his appointment "signals the end of 20 years of interventions that began with Somalia and ended with Iraq and, very soon, Afghanistan".

Gong Li, director of the Institute of International Strategic Studies of the Party School of the Communist Party of China Central Committee, said Kerry is more "modest and prudent" than Hillary Clinton, the current US secretary of state.

"He may reduce military adventurism, and do more things to repair US relations with major powers, including Russia and China," Gong said of Kerry.

Although the general framework of US foreign policy may not change, Kerry may take a moderate approach and make subtle changes in the US "pivot to Asia" policy, Gong said.

Debates in the US have surfaced over whether that country should be overly involved in the island disputes between China and Japan when the US still faces troubles in the Middle East.

Whether the US can afford its current foreign policy when its domestic economy faces so many problems is also a hot debate topic in Washington.

Gong said the criticism of US foreign policy is likely to become louder after Kerry and Hagel take office.

"For China, it's an opportunity to improve Sino-US relations. China should seize such positive signals sent out from the US side, have strategic talks and try to minimize certain conflicts," Gong said.

Kerry has visited China many times and has contacted several generations of China's top leaders.

In 2000, he voted in the Senate in favor of establishing permanent normal trade relations with China.

He also criticized then-president George W Bush's policy on Taiwan, when Bush committed the US to defending Taiwan militarily against China in 2001.

What Hagel, the possible next defense secretary, will face is a question about whether the US should treat China as a nation its military has to confront sooner or later, or as a nation with which it can coexist peacefully.

An article in The National Interest called Hagel "a China dove" who "does not join those who are alarmed by the fact that the Chinese economy has been growing at a rapid clip".

"One can assume that he will help President Obama reign in those in the Pentagon who see China as a threatening adversary and are making moves that, however inadvertently, slide the United States toward a new Cold ― if not shooting ― War with China," the article said.

In an interview with PBS in January, Hagel said: "China is going to emerge and grow. It should; we should welcome that. … Everything that we have to have in our country to prosper, so do the Chinese".