China said Friday it opposed invoking sanctions on Iran over its nuclear programme after three Western nations told the UN they would reimpose them if no diplomatic solution was found by the end of August.
European sanctions on Iran were eased after a 2015 deal in return for curbs on Tehran's nuclear programme.
But on Wednesday, foreign ministers from the E3 group -- Britain, France and Germany -- threatened to reimpose them in a joint letter to United Nations Secretary-General Antonio Guterres and the Security Council.
China said Friday it "opposes invoking" sanctions and "believes that it does not help parties build trust".
Reimposing sanctions was "not conducive to the diplomatic effort for the early resumption of talks", Beijing's foreign ministry spokesman Lin Jian said in a statement.
Iran said Thursday it was working with China and Russia to stop the return of the sanctions.
European countries have stepped up warnings to Iran about its suspension of cooperation with the UN nuclear watchdog, the International Atomic Energy Agency.
That came after Israel launched a 12-day war with Iran in June, partly seeking to destroy its nuclear capability. The United States staged its own bombing raid during the war.
Wednesday's E3 letter sets out engagements that the ministers say Iran has breached, including building up a uranium stock to more than 40 times the permitted level under the 2015 deal.
"The E3 remain fully committed to a diplomatic resolution to the crisis caused by Iran's nuclear programme and will continue to engage with a view to reaching a negotiated solution," the ministers said.
- 'Tools to respond' -
The 2015 deal, known as the Joint Comprehensive Plan of Action, or JCPOA, effectively collapsed after US President Donald Trump withdrew from it in 2018 during his first term and restored sanctions.
European countries attempted to keep the deal alive.
The agreement, which terminates in October, includes a "snapback mechanism" allowing sanctions to be restored.
Iran's foreign minister Abbas Araghchi said the return of sanctions would be "negative" but that the predicted economic effects "have been exaggerated".
"We will try to prevent it," he told state TV on Thursday.
"If this does not work and they apply it, we have tools to respond. We will discuss them in due course."
Last month, Araghchi sent a letter to the UN saying the European countries did not have the legal right to restore sanctions.
The European ministers called the claim "unfounded".
"Any moves taken by the Security Council now should help reach new agreements in talks, instead of the opposite," China's Lin added on Friday.
