China urged all parties to the Iran nuclear deal to uphold the pact on Wednesday after Tehran unveiled plans to boost uranium enrichment capacity following Washingtons pullout from the agreement. "Under the current situation, we hope that all parties concerned can proceed with the long-term and overall interests in mind and continue to sustain and implement the agreement," Chinese foreign ministry spokeswoman Hua Chunying told a regular press briefing. "A comprehensive agreement and a thorough and balanced implementation of its obligations will help maintain the international system to ensure nuclear non-proliferation and help maintain peace and stability in the Middle East," she said. The move comes a month after President Donald Trump announced the US decision to withdraw from the deal and reinstate sanctions. The remaining parties -- China, Britain, France, Germany and Russia -- have vowed to stay in the accord. Irans president, Hassan Rouhani, will meet with Chinese leader Xi Jinping at the summit of the Shanghai Cooperation Organisation, a regional security group, in the eastern city of Qingdao this weekend. Russian President Vladimir Putin will also attend the conference. Iran informed the UN nuclear watchdog of “tentative” plans to produce the feedstock for centrifuges, the machines that enrich uranium, the agency said on Tuesday. Iranian Supreme Leader Ali Khamenei said on Monday he had ordered preparations to increase uranium enrichment capacity if its nuclear deal fell apart after US President Donald Trump announced his country’s withdrawal last month. “The Agency received a letter from Iran on 4 June informing the Agency that there is a tentative schedule to start production of UF6,” a spokesman for the International Atomic Energy Agency (IAEA) said, referring to uranium hexafluoride, the feedstock for centrifuges. The deal allows Iran to enrich uranium to 3.67 percent — far below the 90 percent of weapons grade — and caps its stock of enriched uranium hexafluoride at 300 kg.