Here are the US exports that could get slapped with retaliation by other countries

  • Countries are widely expected to respond with countermeasures to Washington's proposed tariffs on foreign steel and aluminum imports
  • A look at U.S. exports to at-risk nations could provide a sense of how the international community may retaliate.

President Donald Trump's tariffs on steel and aluminum imports has triggered sharp criticism from the international community, begging the question of how the world will react.

It's still too early to tell how other governments may respond — so far, Canada and the European Union have promised strong countermeasures but didn't provide details.

If the administration applies its tariffs to all steel and aluminum exports — as opposed to cherry-picking countries to punish — there are five nations that will suffer the most. Brazil, Canada and South Korea were the three largest suppliers of steel to the U.S. last year, according to data from IHS. Canada, Russia and the U.A.E. were the three largest suppliers of aluminum in 2016.

Cornell University Professor Eswar Prasad told CNBC that countries may hit back in the form of "surgical strikes," meaning they may choose to target specific U.S. products.

For that reason, it's worth looking at what the United States is selling to the nations most at risk from Trump's tariffs.

Below are the U.S.-made products that make up the largest percentage of total exports to those five countries, based on 2016 data from the Observatory of Economic Complexity, an MIT site that compiles international trade statistics.

Canada

  • Vehicle parts are 6.4 percent of U.S. exports to Canada
  • Cars: 5.5 percent
  • Delivery trucks: 4 percent
  • Refined petroleum: 3 percent

Brazil

  • Refined petroleum: 12 percent
  • Packaged medicaments (chemical products): 2.4 percent
  • Medical instruments: 2.1 percent
  • Wheat: 1 percent

South Korea

  • Integrated circuits: 6.4 percent
  • Cars: 3.7 percent
  • Photo lab equipment: 4.5 percent
  • Corn: 2.1 percent

Russia

  • Construction vehicles: 4.2 percent
  • Vehicle parts: 3.2 percent
  • Cars: 2.8 percent
  • Soybeans: 1 percent

UAE

  • Cars: 8.7 percent
  • Broadcasting equipment: 5.8 percent
  • Gold: 3.7 percent
  • Explosive ammunition: 3.7 percent