The opening of the new office follows a series of safety scares over Chinese-made products.
The most recent alert has centred on the Chinese dairy products tainted with the industrial chemical melamine.
After meetings with Chinese officials on Tuesday, Leavitt said China and the US would work on a joint initiative to use better technology for detecting contamination, demand greater corporate responsibility and increase sharing of data and information.
In the past year, China has stepped up inspections and tightened restrictions on food production and other industries, after a series of scandals.
However, analysts say it remains an uphill climb for Chinese authorities to regulate countless small and illegally run manufacturing operations.
Shao Mingli, head of China's country's food and drug administration, said the opening of the FDA office was a "very clear signal to the whole world."
"As food and drug regulatory agencies, our first priority is to protect public health and life," Shao said at Wednesday's ceremony. "This is our top responsibility."
The FDA says it plans to open further offices in India, Latin America and Europe in coming months as it tries to step up safety monitoring of more than $2 trillion worth of goods imported into the US every year.