President Donald Trump blasted China on Monday, Aug. 5, accusing Beijing of “currency manipulation” and “major violation” after it devalued the yuan below the psychological level of 7 units per U.S. dollar for the first time in more than a decade.

“China dropped the price of their currency to an almost a historic low,” the president tweeted. “It’s called ‘currency manipulation.’ Are you listening Federal Reserve? This is a major violation, which will greatly weaken China over time!”

The accusation comes after China’s central bank allowed its currency to drop to 7.02 yuan per U.S. dollar on Aug. 5, the weakest since 2008, during the global economic crisis.

The yuan fell below a sensitive threshold several days after President Trump announced his administration would impose a 10% new tariff on an additional $300 billion in Chinese imports from Sept. 1, prompting China to signal its retaliatory measures.

In the previous retaliations since the trade war escalated last summer, China has been imposing tariffs on $110 billion worth of U.S. goods and now lacks U.S. imports to tax. A devaluation of currency maybe a measure Beijing seeks to come to.

A weaker yuan can make China’s exports cheaper and help counteract tariffs from President Trump.

The Trump administration decided in May not to label any country as a currency manipulator, but warned it was closely monitoring China for such actions.

And in his series of tweets on Monday, President Trump repeatedly stressed the phase “currency manipulation” by China.

“Based on the historic currency manipulation by China, it is now even more obvious to everyone that Americans are not paying for the Tariffs – they are being paid for compliments of China, and the U.S. is taking in tens of Billions of Dollars! China has always used currency manipulation to steal our businesses and factories, hurt our jobs, depress our workers’ wages and harm our farmers’ prices. Not anymore!” he wrote.

“China is intent on continuing to receive the hundreds of Billions of Dollars they have been taking from the U.S. with unfair trade practices and currency manipulation. So one-sided, it should have been stopped many years ago!” he continued.

On Saturday, President Trump also insisted that China is paying for his tariffs while U.S. consumers are paying nothing, given low inflation in the United States now.