China expressed opposition on Wednesday to external interference in a country's internal affairs and disapproval of the use or the threat of force in international relations following comments by US President Donald Trump suggesting Washington could take strong action if Iran executes more protesters.

Foreign Ministry spokeswoman Mao Ning made the remarks when responding to a media query on the situation in Iran.

"We hope all sides could do more that are conducive to the peace and stability in the Middle East," Mao told a daily news conference.

China also supports and hopes that the Iranian government and its people could overcome the current difficulty and maintain stability in the country, she said.