China urged Iran on Wednesday to consider international concerns over its nuclear programme and be constructive, but added all sides should remain calm.
The Foreign Ministry said it had received Iran's response to a package of proposals to resolve the nuclear standoff with the West and was "conscientiously" studying it.
"The Chinese side hopes Iran earnestly considers the concerns of the international community, and takes the necessary constructive steps," the ministry said in a faxed statement.
"We also hope that other parties remain patient and calm," it said.
Iran on Tuesday handed over its formal response to a nuclear incentives offer from major powers and said it contained ideas that would allow serious talks about its standoff with the West to start immediately.
But Tehran gave no sign of heeding a key UN Security Council demand that it freeze uranium enrichment before the end of this month or face the prospect of sanctions.
China, along with Russia, is a key trading partner with Iran and opposes sanctions.
China's foreign ministry statement made no mention of sanctions, saying instead it believes diplomatic talks were the best way to resolve the problem.
China "upholds the direction of a peaceful resolution, to create the best conditions for the early resumption of talks".
The world's fourth largest oil exporter, Iran says it will not abandon what it calls its right to enrich uranium for use in nuclear power stations. Western countries fear Iran wants to master enrichment to give it the ability to make atomic bombs.
The UN Security Council - frustrated with Iran's slow response to the incentives offer made by Britain, Germany, France, China, the United States and Russia in June - has given it to August 31 to freeze enrichment or face possible sanctions.
Iran has called the deadline illegal and worthless and China has said talk of sanctions of use of force is unhelpful.