Tung Chee Hwa, former chief executive of Hong Kong, said yesterday at the Harvard Kennedy School that the single most important bilateral relationship for the world is the one between the United States and China. But, he said, this relationship can only been described as passive tolerance today.

“Our challenge now,” he said, “is how you can lead this relationship forward.”

Tung held the highest administrative post of Hong Kong for eight years after Britain returned Hong Kong’s sovereignty to China in 1997. This January he founded the China-United States Exchange Foundation, hoping to improve communications between the two countries.

The talk took place amid an unprecedented global economic crisis that started in the United States but is rippling around the globe and now challenging the Chinese economy that has been booming for more than two decades.

“Both countries should take active steps to improve trading,” Tung said. “That’s the only way to avoid protectionism.”

But Tung admitted that domestic policies in both countries threaten the prospect of trading.

“The benefit of globalization is not being shared very well, not in China, not in the United States. It should be shared better,” Tung said.

Yet, he said that China and the United States are the beneficiaries of the global economy, and he described the bilateral relationship as a “win-win relationship.”

The talk attracted a packed audience of nearly 200 people at the Starr Auditorium at the Kennedy School.

“I wish I could say that he is a Kennedy School graduate, because he is certainly the model of many of you here at the Kennedy School,” said the school’s dean, David T. Ellwood ’75, in the welcoming remarks.

“I’ve seen him on TV. I know he is a big deal,” said James V. Secreto, a first-year student at the Kennedy School. Secreto spent two years working and studying in China after college.

Talking about Tung’s comment on trading, Secreto said that domestic policies can be a challenge. “He talked about it, but he didn’t address the feelings of auto worker in Michigan or the factory workers in Ohio, who think that China is taking away their jobs. Those feelings are real. Yes, we need more trade, but there are more serious problems.”