Trade talks between the U.S. and China have reportedly hit another obstacle, delaying the “phase one” accord President Trump and Chinese Vice Premier Liu He announced on October 11. The Wall Street Journal reports that the Chinese are resistant to committing to specific agricultural purchases and limits on technology transfer. And in talks with reporters last Friday, President Trump cast doubts on the tariff rollbacks, which are considered a key commitment in any deal by the Chinese.

Previously, President Trump said the Chinese had committed to purchasing $50 billion in U.S. agricultural products, including soybeans and pork. People familiar with the negotiations have told the Journal that the Chinese don’t want the farm purchases in the deal laid out so explicitly. Chinese officials are also pushing back on other U.S. demands, notably an enforcement mechanism supporting any deal and the requirement that companies doing business in the country share technology with Chinese partners.

China has linked its demands to the rollback of U.S. tariffs on Chinese imports. CNBC reports that at a press conference today, China Ministry of Commerce spokesperson Gao Feng said, ““The trade war was begun with adding tariffs and should be ended by canceling these additional tariffs. This is an important condition for both sides to reach an agreement. If both sides reach a phase one agreement, the level of tariff rollback will fully reflect the importance of the phase one agreement.”

Along with the farm purchases, in the phase one deal U.S. negotiators are also pursuing Chinese agreements on currency manipulation prevention, intellectual property manipulation and an opening up of the country’s financial markets.