"China has always held that sanctions should not be lightly imposed in international relations. Dialogue and negotiations are the best approach to resolving the Iranian nuclear issue," the ministry said in a brief statement in response to a question from The Associated Press.
"To impose new sanctions on Iran at a time when international society and the Iranian authorities are working hard to find a solution to the Iranian nuclear issue can only complicate the issue," the statement said.
The new U.S. sanctions are the most sweeping since 1979, cutting off more than 20 Iranian entities, including individuals and companies owned or controlled by the powerful Revolutionary Guard Corps, from the American financial system.
Washington has long labeled Iran a state supporter of terrorism and has been working for years to gain support for tougher sanctions from the international community aimed at keeping the country from developing nuclear weapons.
Washington has already won two U.N. Security Council sanctions resolutions, but Russia and China, both veto-wielding permanent council members, have said they will not support further sanctions from the body.
China's stance reflects its disdain for any measure it considers as interference in another country's internal affairs. However, China's need for export markets and energy have prompted it to draw close to Iran and Sudan, undermining attempts by the West to isolate those regimes over human rights and other issues.