U.S. stock futures fell Sunday after another rough week on Wall Street, and as China threatened to retaliate against countries that cooperate with U.S. trade restrictions.

Accusing the U.S. of “unilateral bullying,” China’s Ministry of Commerce said “China firmly opposes any party reaching a deal at the expense of China’s interests. If this happens, China will not accept it and will resolutely take reciprocal countermeasures.” The Trump administration is planning to pressure its trade partners to reduce trade with China in exchange for tariff relief, the Wall Street Journal reported last week.