U.S. stock benchmarks cut solid gains Thursday morning after a tweet from President Donald Trump indicated that trade talks between China and the U.S. may not be making substantial progress. Trump tweeted that China is “letting us down” by not buying U.S. farm products “that they said they would.” Trump’s tweet comes amid reporting that the administration is increasingly concerned over the prospect of a Sino-American trade resolution, amid a reshuffling of the Chinese negotiating team. Trump said at last month’s G-20 meeting in Osaka, Japan that Chinese President Xi Jinping had agreed to order large new purchases of U.S. agricultural goods “almost immediately.” The Nasdaq Composite Index COMP, +0.00% which tends to be sensitive to news on trade progress, turned negative after opening solidly higher. The index was flat but in the red at 8,201, but had been as high as 8,222, according to FactSet data. The Dow Jones Industrial Average DJIA, +0.50% meanwhile, held on to positive territory but was off its best levels–briefly breaking above a milestone at 27,000 –up 0.4% at 26,957 and the S&P 500 index SPX, +0.07% was trading up less than 0.1% at 2,995, but had hit a high at 3,002.18 intraday.