Iran's chief nuclear negotiator said on Thursday the West had failed in efforts to put pressure on the Islamic Republic over its atomic activities.
The West fears Tehran is seeking an atom bomb and has imposed two sets of United Nations sanctions. Iran says it aims only to generate electricity.
"Those countries who so far have been after imposing sanctions and putting pressure on Iran have not achieved any success," chief nuclear negotiator Saeed Jalili told the official IRNA news agency at the start of a visit to Beijing.
"Today, global developments and Iran's logical behavior do not allow anybody to do this."
A US Intelligence report last month said Iran stopped an active nuclear arms drive in 2003, compounding international disagreement over the next steps regarding Iran.
China and Russia, veto-wielding UN Security Council members, have balked at more sanctions resolutions on Tehran.
Germany: Increase sanctions on Iran
Jalili said Iran and China, which imports large amounts of oil from the Islamic state, enjoyed good relations.
Iran's OPEC governor, Hossein Kazempour Ardebili, said he did not believe the UN Security Council would be able to agree on new sanctions against Tehran.
"In my opinion it is unlikely that the Chinese and Russians would join a third resolution," He told the Iran daily. Any sanctions on investments in Iran's energy sector could endanger security of supply and hit consumer countries, he said.
Germany said on Wednesday it wanted a UN resolution increasing sanctions on Iran and major powers plan to meet in Berlin on Tuesday to discuss strategy.
German Foreign Minister Frank-Walter Steinmeier will first consult in Vienna on Thursday with International Atomic Energy Agency Director Mohamed ElBaradei.
The UN Nuclear watchdog chief held talks in Tehran last week to seek swifter cooperation with a long IAEA inquiry into Iran's nuclear history and an end to curbs on UN Inspections meant to ensure its present program is wholly peaceful.
ElBaradei returned with an agreement from Iran to answer remaining questions within a month about past, covert nuclear work that had military applications.
Iranian officials have said new sanctions could hurt its cooperation with the UN nuclear body.