President Donald Trump signed an executive order on Thursday evening to impose tariffs of between 15 and 41 percent on goods shipped to the U.S. from more than 67 countries, ratcheting up tariff levels to the highest amount in more than a century.

The new duties, however, won’t go into effect until Aug. 7 — giving countries yet another window to try and negotiate them down.

“This is historic, this is a new system of trade,” said a senior administration official, granted anonymity as part of the terms of a call. “It’s what I would call the Trump round of negotiations.”

According to the text of the order, the Trump administration is maintaining its 10 percent so-called baseline tariff to countries where the U.S. has a trade surplus — i.e. it sells more American products to those countries than it imports from them. And it officially imposes the agreed-upon 15 percent rate that Trump set as part of trade agreements with leading trading partners like the European Union, Japan and South Korea. The Philippines, Vietnam and Indonesia also reached tentative agreements with the administration that set their duties at 19-20 percent.

Other countries, mainly smaller economies, face far higher rates, topping out at 41 percent for Syria, which is emerging from a civil war, and 40 percent for Myanmar, which is still in the midst of one. The Southeast Asian nation of Laos also faces a 40 percent tariff, and Iraq will be hit with a 35 percent duty.

Bigger trading partners like Switzerland and Taiwan also face significant hikes — to 39 percent and 30 percent respectively.

The order suggests that Trump decided to punish countries that he did not believe offered enough concessions during the flurry of negotiations that countries have engaged in since the White House first rolled out its plan for “reciprocal” tariffs on April 2.

“Some trading partners have agreed to, or are on the verge of agreeing to, meaningful trade and security commitments with the United States, thus signaling their sincere intentions to permanently remedy the trade barriers,” it says.

“Other trading partners, despite having engaged in negotiations, have offered terms that, in my judgment, do not sufficiently address imbalances in our trading relationship or have failed to align sufficiently with the United States on economic and national-security matters,”

“There are also some trading partners that have failed to engage in negotiations with the United States or to take adequate steps to align sufficiently with the United States on economic and national security matters,” it continues.

White House officials said Thursday night that they expect to strike additional agreements with countries ahead of the new, Aug. 7 implementation date for the tariffs. “We have some deals, and I don’t want to get ahead of the president on those deals,” the senior administration official told reporters. “I’ll just say generally, we have more to come.”