China’s foreign minister, Wang Yi, on Thursday urged all parties involved in talks on Iran’s nuclear program to make no new demands and respect the legitimate concerns of the participants, Reuters reports.

Wang, who is in Russia, said the situation had become more complex now that the talks process was in its final stages but that everyone should be patient.

“(We) must push forward the next stage of talks on the basis of the Lausanne framework … and all parties should not raise any new demands to prevent complicating the talks process,” Wang told his Russian and Iranian counterparts, according to Reuters.

“All sides’ legitimate concerns ought to be paid attention to and rationally resolved; all sides should meet each other half way and not drift further apart,” he added.

A swift agreement would benefit the global non-proliferation system as well as regional peace and stability, and China would continue to play a constructive role, he said.

China and Iran have close diplomatic, economic, trade and energy ties, and China has repeatedly urged Iran to reach an agreement.

Iran and the six world powers are holding ongoing discussions aimed at turning a preliminary deal into a permanent one by a June 30 deadline.

The sides made a major breakthrough at talks with Iran on April 2 by agreeing on the parameters for a final deal to scale back its nuclear capabilities, but still have a series of technical issues to resolve by the looming deadline.

Last week, Iran told world powers not to make “excessive demands” in the talks, apparently in response to France’s demand to inspect its military installations suspected as serving a covert role in developing nuclear weapons.

“I would expect my negotiating partners to refrain from making excessive demands,” Iranian Foreign Minister Mohammad Javad Zarif said. “People need to have their foot in reality, not in illusions.”

Zarif further said he hopes a final nuclear agreement will be reached “within a reasonable period of time.”

“If the other side respects what has been agreed in Lausanne and tries to draft based on mutual respect a comprehensive agreement with Iran that is sustainable…then we can meet any deadline,” he said.

Shifting his tone, Zarif continued, “If people insist on excessive demands, on renegotiation, then it will be difficult. I am hopeful we will reach a final conclusion within a reasonable period of time.”