CEOs of leading American steel companies sent a letter to President Trump on Friday, urging him not to provide any exceptions or exclusions to the planned steel tariffs set to go into effect on March 12.

The letter, obtained by NewsNation, has been signed by the CEOs of companies such as US Steel Corporation, Cleveland-Cliffs and Nucor.

The letter said that the steel tariffs enacted by Trump in his first term were welcome but that “subsequent negotiations opened the door to renewed increased import volumes, diluting the program’s effectiveness…”

“The result was a weakened U.S. steel industry exposed again to the global steel oversupply crisis,” the letter adds. 

The CEOs told Trump in the letter that his Feb. 10 proclamation reinstating a uniform 25 percent tariff across the board “is the right response to this global challenge.”

“We urge you to resist any requests for exceptions or exclusions and to continue standing strong on behalf of American steel,” the letter said.

The CEOs said this move would “revitalize” the American steel industry, which they called “a matter of national security.”

The Trump administration is seeking to revive policies enacted during the president’s first term to include a 25 percent tariff on all steel imports.

Argentina, Australia, Brazil, Canada, Japan, Mexico, South Korea, the European Union, Ukraine and the United Kingdom were exempt from the taxes on steel and aluminum imports during the first Trump administration. This time around, the administration has argued their exclusion “prevented the tariffs from being effective.”

Trump is also planning to raise his original 10 percent tariffs on aluminum imports from 2018 to match the 25 percent duty on steel. The policy will be imposed on all countries across the globe, unlike his prior directive.  

The president’s proposed tariffs across industries have cause international uproar, with some global leaders calling it a trade war. Canadian Prime Minister Justin Trudeau has called the tariffs “dumb” while Mexican President Claudia Sheinbaum warned of retaliatory tariffs. Trump delayed the taxes set to hit Mexico until April.