Beijing needs to be made aware, he said, of how important changing the bilateral trade and business relationship is to the welfare of American workers.
"We've had a situation for many years where China has not treated American companies fairly and the trade deficit has grown and grown and grown," Branstad said.
For instance, Chinese chat app WeChat can be used in the U.S., while Facebook is blocked in China, he added.
"We want to continue to build the trade relationship with China, but China needs to really change some of its unfair and discriminatory policies," Branstad said.
Although China has pledged to liberalize its economy, "three or five years from now is not soon enough, it needs to happen quicker and that's what we're working to try to get accomplished," he said.
After all, Chinese workers "have seen a tremendous improvement in their standard of living over the last 20 years but American workers, many have seen none and we have seen a lot of the jobs go overseas," he said.
Chinese officials need to be aware, therefore, of "how critically important this is to American workers," he said of the U.S.'s angling for a more beneficial trade relationship.
Beijing said last week it may target 128 U.S. products with an import value of $3 billion as retaliation for President Donald Trump signing an executive order earlier this month that imposed broad duties on foreign aluminum and steel imports.
Trump also announced tariff plans for up to $60 billion in Chinese imports last week, but China did not officially connect its threats to that White House action.
The chances of a trade war appeared to lessen, however, based on reports out Monday: The Financial Times said China had offered to buy more semiconductors from the U.S. to help cut the trade imbalance, and The Wall Street Journal reported officials in both countries are working to improve American access to Chinese markets.
On Thursday, China's Commerce Ministry Gao Feng told a regular briefing that the U.S. trade measures on China were typical trade protectionism and reflected a Cold War attitude, Reuters reported.