Tariffs on $200 billion of Chinese imports will increase to 25 percent from 10 percent on Friday, and another $325 billion in goods will “shortly” be subject to tariffs, President Donald Trump said Sunday, in a warning to China as what could be a closing round of takes for a trade deal are set to start in Washington this week.

Trump suggested in announcing the move on Twitter that he was acting because he’s not satisfied with the pace of progress in negotiations with China.

“The Trade Deal with China continues, but too slowly, as they attempt to renegotiate,” Trump said in his tweet. “No!”

Chinese President Xi Jinping’s top trade envoy, Liu He, returns to Washington this week for what could be a closing round of trade talks. The White House has ramped up pressure to reach a deal, warning it could still walk away from the months-long negotiations.

Trump and the Chinese president will decide after the negotiations this week whether they’ll meet to sign off on a pact. White House spokeswoman Sarah Sanders said Thursday.

Trump imposed duties of 25 percent on an initial $50 billion of Chinese goods last year and then 10 percent on an additional $200 billion in products. Those duties were set to rise to 25 percent on March 1, but Trump delayed that as talks continued.

Trump also said that tariffs paid by China “are partially responsible for our great economic results,” although it is companies that import Chinese goods, not China itself, that pay the bulk of the additional costs.