China aims to buy at least $20 billion of agricultural products in a year if it signs a partial trade deal with the U.S., and would consider boosting purchases further in future rounds of talks, people familiar with the matter said.

The $20 billion would take its imports of U.S. farm goods back to around the level in 2017, before the U.S. began imposing tariffs. In the second year of a potential final deal when all punitive tariffs are removed, those purchases could rise to $40-$50 billion, said the people, who asked not to be named discussing the private talks. The people did not say when the first year would start or when China would start counting agricultural imports toward the $20 billion.

The two nations are currently working on the details of a limited agreement, after talks in Washington earlier this month at which the U.S. agreed not to hike tariffs in October, and said China agreed to increase purchases and other concessions. If the negotiations go well, Trump and President Xi Jinping may meet in Chile next month to sign the deal. Commerce Secretary Wilbur Ross said any agreement on structural issues will come in two additional phases.

China’s Ministry of Commerce didn’t immediately respond to a fax seeking comment on agricultural purchases.

China has already started ramping up purchases to lay the groundwork for the signing of a phase one deal. Beijing issued waivers for 10 million tons of soybean purchases this week. It is considering approving an additional 4-5 million tons of grains, including wheat, corn and sorghum, according to the people, who didn’t provide specific volumes for each commodity.