China remains vague on how much the country will increase purchases of U.S. farm goods, considered a critical part of a trade agreement with Washington.

Han Jun, vice minister of agriculture and rural affairs, confirmed to Chinese financial news site Caixin that import quotas for wheat, corn and rice will not increase.

"These are global quotas. We will not adjust them just for one country," Han told Caixin, according to a CNBC translation of his Chinese-language quotes in an article published Tuesday.