The diplomatic wisdom of incoming US Secretary of State John Kerry is expected to improve China-US relations, as the Obama administration seeks to rebalance its Asian strategy during the president's second term.

President Barack Obama on Saturday nominated Senator Kerry, the son of a diplomat, as his next secretary of state to replace Hillary Clinton, and commentators say that given his track record and reputation, his appointment is almost certain to be confirmed.

Among the challenges facing Kerry will be to improve ties between China and the US, which have worsened since Washington's rebalancing policy in the Asia-Pacific region, experts said.

"China-US ties have deteriorated through a series of high-profile measures by the US aimed at rebalancing, especially the over-emphasis of military action, which triggered great antipathy from China," said Ruan Zongze, a US studies researcher and the deputy director of the China Institute of International Studies.

Kerry supported the Trans-Pacific Partnership trade agreement, to "balance China's economic influence in the region" in a speech at the Center for American Progress before President Hu Jintao's visit to the US in January 2011.

"Some called this intensified US engagement in Asia a hedging strategy, an insurance against the possibility of China emerging as a regional hegemony.

"Frankly, I don't care what we call it. I just think it makes sense that we ought to do it", he said then. During the address he appealed for maintaining a cooperative attitude toward China, rather than one that treated China as an enemy or the cause of US domestic problems.

"If China succeeds in rebalancing its economy, then the global economy will benefit and so will we," he said.

"If China fails — or worse, if we cut ourselves off from China in a misguided attempt to 'contain it' as some have suggested — then we will all suffer. And even though we can't call China an ally today, we simply cannot treat it as an enemy."

Ruan views Kerry as professional, calm and pragmatic, and expects him to initiate strategic dialogues between China and the US, which will wield positive influence on Sino-US relations.

As the new secretary of state, and a supporter of the Asian rebalancing strategy, Kerry would be less aggressive than his predecessor Clinton, said Jin Canrong, an international affairs professor at Renmin University of China.

In an era when being secretary of state is increasingly about style as much as substance, many foreign-policy experts said the five-term senator and quiet negotiator is expected to return the office to a more traditional version of diplomacy, according to The Christian Science Monitor.

The Vietnam veteran, who was critical of the war after he returned home, lost to US president George W Bush in the 2004 election.

He has represented Massachusetts in the senate since 1985, and has served as chairman of the Senate Foreign Relations Committee for decades.

During his first term, Obama sent Kerry around the world on his behalf numerous times, particularly to Afghanistan and Pakistan.

He also helped prepare the president for his live TV debates during this year's election, and won praise from Obama for his sharp national security-focused speech at the Democratic National Convention in August, when he told delegates: "Ask Osama bin Laden if he's better off now than he was four years ago."

Contact the writer at zhouwa@chinadaily.com.cn