US President Donald Trump is arguing that value added taxes, or VAT, and export subsidies can also be reasons for Washington to impose what he calls reciprocal tariffs.

On Thursday, Trump signed a plan to introduce a reciprocal tariffs scheme, in which the US will match what it considers high levies other countries have placed on American goods.

In a social media post on Saturday, Trump wrote, "For many years, the US has been treated unfairly by other countries, both friend and foe." He argued that reciprocal tariffs will immediately bring fairness and prosperity back into the trade system.

He also said targets for reciprocal tariffs can also be countries with non-tariff trade barriers to "keep our products out of their domain, or if they do not even let US businesses operate."

Trump said that if countries feels US tariffs on their products are too high, "all they have to do is to reduce or terminate their tariff against us."