The Chinese Foreign Ministry said on Tuesday that tariff wars benefit no one and vowed to safeguard its legitimate interests after U.S. President Donald Trump threatened sweeping duties on countries that do business with Iran.

Responding to a question at a press conference, Foreign Ministry spokesperson Mao Ning said China's position on tariffs has been very clear, stressing that there are no winners in tariff wars. 

China will firmly defend its legitimate and lawful interests, she added.

Mao's remarks came after Trump said in a social media post on Monday that any country conducting commercial exchanges with Iran would face a 25-percent tariff on all trade with the United States.