The Wall Street Journal reports that President Trump threatened to drastically ramp up U.S. tariffs on Chinese imports, a surprise twist that put an accord in doubt as Beijing considered pulling out of talks scheduled to begin this week. In a pair of Twitter messages Sunday, Mr. Trump wrote he planned to raise levies on $200 billion in Chinese imports to 25% starting Friday, from 10% currently. He also wrote he would impose 25% tariffs "shortly" on $325 billion in Chinese goods that haven't yet been taxed. "The Trade Deal with China continues, but too slowly, as they attempt to renegotiate," the president tweeted. "No!" Mr. Trump's tweets surprised many Chinese officials, according to a person briefed on the matter Monday, and China is considering canceling trade talks that are to resume in Washington starting Wednesday. There has been widespread expectations in recent days that an accord could be reached by Friday. "China shouldn't negotiate with a gun pointed to its head," the person said. A decision on whether to go ahead with the talks this week hasn't been made, the person said.

Reuters reports that Canada is leaning on the United States to help settle a dispute with China, which has started to block imports of vital Canadian commodities amid a dispute over a detained Huawei executive. In a sign of increasing frustration at what it sees as a lackluster U.S. response, Prime Minister Justin Trudeau's government is signaling it could withhold cooperation on major issues. China has upped the pressure on Canada in recent weeks over the arrest of Huawei Technologies Co Ltd Chief Financial Officer Meng Wanzhou, arrested last December on a U.S. warrant. It halted Canadian canola imports and last week suspended the permits of two major pork producers. After Meng's Vancouver arrest, Chinese police also detained two Canadian citizens. Beijing is refusing to allow a Canadian trade delegation to visit, forcing officials to use video conference calls as they try to negate a major threat to commodity exports. With no cards to play against China without risking significant economic damage, Canada has launched a full-court press in Washington, which is negotiating its own trade deal with Beijing.