China is threatening to retaliate once again against rising U.S. tariffs, but the Asian country has literally run out of U.S. exports to put new taxes on.

Mexico’s new 350,000-metric-ton quota for tariff-free pork imports is full, and none of that meat will likely be provided by U.S. producers, according to officials at USDA’s Foreign Agricultural Service. The quota was briefly seen as a potential lifeline for U.S. pork exporters, who were hit last week by Mexico with a 10 percent tariff that increases to 20 percent on July 5.

U.S. farmers and ranchers have a lot to gain from the ongoing trade talks with China, but even more to lose if the two countries cannot come to an agreement on protecting U.S. intellectual property.