Winston Lord was the United States ambassador to China between 1985 and 1989, but his connection to China was actually formed long before he took the post. As a member of the National Security Council's planning staff from 1969 to 1973, he was an aide to National Security Adviser Henry Kissinger and accompanied Kissinger on his secret trip to Beijing in 1971. He was also part of the US delegation during President Richard Nixon's historic visit to China in 1972.

Though relations between the US and China have gone through twists and turns over the past three decades, Lord said he think the two nations have been heading toward a more stabilized relationship since the 1990s.

"When I was in Clinton's administration, we set up a stabilized relationship ever since - not by the governments, but by the public," said Lord, 74, who served as assistant secretary of state for East Asian and Pacific Affairs during President Bill Clinton's first term.

Lord calls the current state of ties "a mixed relationship".

"China has made great achievements but still has problems like its political system that both sides disagree over," said Lord, adding that both countries should try "to maximize cooperation and contain inevitable tensions".

"I think it's settled now to a fairly balanced view that we should be friends, but we are not going to be allies, we are not going to be enemies - it's going to be a mixed relationship," Lord said.

China and the US are major trading partners, with trade reaching $385.3 billion last year, which is 160 times the volume from when the two established diplomatic relations in 1979.

When asked how the US looks upon China's rise, Lord said he is optimistic about the economic relationship between the two countries and said it's wrong to use China as a scapegoat for the US' problems.

"We should not see China's rise as a threat but as an opportunity," Lord said, adding that the US should try to put itself in China's shoes and be sensitive to China's interests.

Orville Schell, director of the Center on US-China Relations at the Asia Society, said China needs to understand that the US has a new kind of vulnerability toward this new power.

"The danger of China being perceived as a threat is that China's rise comes precisely at the same time when the US has a lot of problems. So you have a growing question of confidence within the US at the same time that China is rising," he explained.

"(It) is not just toward China but also Brazil, South Africa and a few other places. So the US is inevitably going to decline in absolute terms and relative terms, but America has its strengths and resilience," Lord said. "If you don't look at per capita but just the overall economy (in China), it is misleading," Lord said.

He said China should stabilize its political, cultural and economic landscapes so that it can focus on developing its domestic standard of life.