"All countries need to refrain from taking actions that further complicate the situation," Fu Cong, director-general of the Department of Arms Control of the Chinese Foreign Ministry told reporters after a three-hour-long meeting of the Joint Commission on the implementation of the Iran nuclear deal in Vienna on Friday.
"In our view, there is an element of automaticity into this and we can't be sure that countries can keep this process under control. It could aggravate tensions," he added.
He said the European powers had not indicated whether they would trigger the mechanism.
However, the Chinese diplomat noted that all parties called on Iran to remain in full compliance of the JCPOA.
Representatives from Iran and the five remaining signatories to the landmark nuclear deal -- Britain, France, Germany, Russia and China --, as well as the European Union, attended the Friday meeting to discuss ways to save the accord.
It was the first meeting by the remaining parties to the JCPOA since July. In May 2018, US President Donald Trump unilaterally pulled his country out of the international deal, in defiance of global criticism, and later re-imposed the sanctions that had been lifted against Tehran as part of the agreement.
In response to the move, Tehran has so far rowed back on its nuclear commitments four times in compliance with Articles 26 and 36, but stressed that its retaliatory measures will be reversible as soon as Europe finds practical ways to shield the mutual trade from the sanctions.
However, European members since last month have begun raising the possibility of triggering the JCPOA's "dispute resolution mechanism," which is also known as the trigger mechanism, and whose activation can lead to the return of the UN sanctions on Iran.