China said on Tuesday it would protect its rights and interests after US President Donald Trump announced a 25 percent tariff on any country doing business with Iran.

"We have always believed that there are no winners in a tariff war, and China will resolutely safeguard its legitimate rights and interests," foreign ministry spokeswoman Mao Ning said when asked about Trump's levy announcement.

The Chinese embassy in Washington also said it opposed "any illicit unilateral sanctions and long-arm jurisdiction."

In a posting on X, an embassy spokesperson said China's position against the indiscriminate imposition of tariffs is consistent and clear.

"Tariff wars and trade wars have no winners, and coercion and pressure cannot solve problems," spokesperson Liu Pengyu said.

In response to a question about advice for Chinese citizens travelling to Iran for tourism purposes, Mao said Beijing was "closely monitoring the development of the situation".

"We will take all necessary measures to protect the safety of Chinese citizens," she said. (AFP/Reuters)