Brazil is preparing to challenge the U.S. again at the World Trade Organization over cotton subsidies, Agriculture Minister Blairo Maggi said in an interview.

A crisis is looming for the World Trade Organization’s dispute resolution system as the Trump administration presses the international body to reform its ways and the U.S. ag sector could be a casualty in the coming showdown.

Brazil, known and often reviled in the U.S. ag sector for its successful World Trade Organization challenge to U.S. cotton support programs, is now suspected breaking WTO rules by subsidizing its rice exports.

In the latest salvo of trade actions between the U.S. and Chinese governments, the Chinese Ministry of Commerce (MOC) announced plans today to impose a 25 percent tariff on $50 billion of U.S. goods, including soybeans, aircraft and automobiles, according to the Chinese News Agency, Xinhua.

U.S. complaints that Europe wasn’t living up to a promise to import American beef were ignored for years, but that’s changed in the months since the Trump administration began considering retaliatory duties on European imports. Now the two sides are talking and it looks like a deal could be in the works.

The U.S. continues to demand Canada dismantle its supply management dairy system as part of the so-far fruitless NAFTA renegotiations, but if that fails, the U.S. is “actively considering” filing a complaint against Canada in the World Trade Organization.

A lot of the action going down now at the 11th World Trade Organization Ministerial in Argentina is likely happening on the sidelines as the U.S. and Brazil hash out new and old disputes over ethanol and wheat that continue to frustrate the American ag sector.