US President Donald Trump is set to rekindle economic pressure on America’s trading partners this week, as a deadline for making trade deals elapses and the administration begins notifying countries of the tariffs they’ll face on exports to the United States.For 90 days, the administration has been trying to reach trade pacts with dozens of countries in an attempt to lower economic barriers to US exports. In April, Trump imposed stiff global tariffs on nearly every trading partner but paused most of those levies until this Wednesday to try and win concessions.So far, the United States has reached only two preliminary trade deals, with the United Kingdom and with Vietnam, which are scant on details and leave much to be worked out.More such limited trade deals could be announced in the coming days, including an initial trade framework with India. Countries that have so far agreed to trade deals, even preliminary handshake agreements, have qualified for lower tariff rates than what Trump threatened in April.Other countries that have not reached agreements are expected to face sharply higher tariffs, although the US president and his advisers have recently implied that the tariffs may not go into effect until Aug. 1, rather than Wednesday.Still, with tariffs threatening to strain diplomatic relations and bring some global commerce to a halt, a delay of a few weeks may not to do much to soothe many foreign governments. It could also further unsettle financial markets, which revolted when Trump initially announced his global tariffs, a meltdown that prompted Trump to institute the 90-day delay.Trump said last week that his administration would begin sending out letters Monday to a dozen trading partners dictating the tariff rates their products would now face, some of which could reach 70%. The president said the tariffs would go into effect Aug. 1.Story continues below this adWhether Trump’s pugilistic approach forces countries to agree to quick trade deals or incites retaliation and trade wars will be a critical test for the president’s extraordinarily aggressive and unpredictable approach to international trade.Since taking office, Trump has raised tariffs to levels not seen in a century, before abruptly pausing many of them. Trump’s supporters argue that his tariff threats have created leverage to forge new agreements and secure better terms for American businesses and the economy. Critics say his tactics have disrupted global trade flows and financial markets and stripped businesses of the certainty they need to plan, resulting in higher prices, less investment and slower economic growth for the country.The US president’s announcement of steep global tariffs in April threw stock and bond markets into turmoil — in part because the levies were incredibly punishing for many of the nation’s biggest trading partners. Trump was persuaded to pause his tariffs for a period of 90 days, which calmed markets, and convinced some investors and analysts that, although the president sees tariff threats as a valuable source of leverage, he would stop short of imposing tariffs at a level that would disrupt markets or cause severe harm to the economy.But in recent months, Trump has repeatedly called that idea into question. In May, he threatened to impose a 50% flat tariff on the European Union, saying the bloc was not offering enough concessions. He then paused those levies until this Wednesday.Story continues below this adTrump continues to profess a belief in the value of tariffs as a way to balance out international trade relationships and finally make the world more fair for U.S. businesses, which he says have long been ripped off by foreigners.While Trump’s advisers praise him as a consummate dealmaker, the president has often seemed more interested in maintaining high tariffs on foreign goods than in striking trade deals that would lower economic barriers for American companies and encourage more international business flows.Speaking to reporters on Air Force One on Friday, the president said he had quickly decided what tariff rate to apply to foreign countries.“I’ve been looking at it for many years,” he said. “Frankly, I think it’s ridiculous that countries were able to get away with so much.”‘People are extremely stretched’Story continues below this adThe government’s trade negotiators have also been overwhelmed as they try to simultaneously hammer out trade deals with multiple partners. Dozens of countries, ranging from South Korea and Malaysia to Lesotho and Switzerland, have reached out to the United States in recent months to try to reach an agreement that would prevent the Trump administration from applying hefty tariffs to their exports.“People are just extremely stretched,” said Wendy Cutler, a vice president of the Asia Society Policy Institute and a former U.S. trade negotiator.Some of those negotiations have proceeded swiftly, propelled by common interests and good relations. Vietnam and the United Kingdom, for example, have agreed to open their markets to US agriculture, buy more Boeing airplanes and cut down on certain ties to China, among other changes.Last week, Trump’s threats against Canada also appeared to produce rapid results. After Trump said in late June that he would suspend trade talks with Canada over its digital services tax on American tech companies, the Canadian government abruptly scrapped the measure.Story continues below this ad“Deals with Vietnam and other countries may very well show that there’s method to the tariff madness,” said Michael Wessel, a longtime trade adviser. “The devil, of course, is in the details, but it’s well past time to rebalance the playing field,” he added.Even for those countries that have struck deals with the Trump administration, tariffs remain extraordinarily high, creating a tax on both American consumers and importing businesses that economists expect to drag on economic activity.Exports from the United Kingdom remain subject to a 10% universal tariff, which the Trump administration shows no signs of dropping, even for America’s closest allies.The preliminary trade deal with Vietnam lowers tariffs on some Vietnamese products to 20% rather than the 46% Trump threatened in April. But many business groups that rely on imports from Vietnam, such as the footwear industry, say that 20% rate will raise costs for American consumers.Story continues below this adIt is also not clear what the deal with Vietnam actually entails. The president announced the agreement with Vietnam on social media last week, but no text or other fact sheets have yet been released by the governments.Other major trading partners, like the European Union and Japan, have proven more challenging to negotiate with. Like other governments, the European Union and Japan remain wary of additional tariffs the president has imposed or is still threatening on their critical sectors, like automobiles, pharmaceuticals and steel. They have also been reluctant to open their markets to American agricultural exports that could undercut their own farmers.If the Trump administration does not strike deals with major trading partners, it could end up stoking trade wars instead. Foreign governments including the European Union have prepared retaliatory packages of tariffs on U.S. exports that they are threatening to impose if hit by further American levies.