President Donald Trump's controversial tariff plan amounts to open war on America's trading partners, who will certainly strike back, according to a leading economist.

Trump's decision to set taxes of 25 percent for steel and 10 percent for aluminum will invite "fairly strong retaliation from trading partners around the world, both targeted and unilateral actions," Cornell University Professor Eswar Prasad told CNBC.

"One lesson that many of America's trading partners have learned is that they need to use surgical strikes to make sure there is political pain exacted on the U.S. government," he continued.

Any redress taken by the international community could follow the White House's lead of bypassing the World Trade Organization, he added: "It could get pretty ugly pretty soon."

For instance, Canada might disrupt the ability of U.S. businesses to use their supply chains effectively, Prasad noted.

"The European Union has already talked about targeting very specific products from the U.S., China has talked about limiting soybean imports and certain high-tech equipment," he continued.