Beijing reiterated on Wednesday its commitment to implementing the Iran nuclear deal and urged all parties concerned to take a responsible and reasonable approach to ensure it remains in place.

"Practice over the past three years has proved fully the deal is effective. China has always believed that safeguarding the deal's integrity and seriousness helps to uphold the international nonproliferation regime, as well as peace and stability in the Middle East," Foreign Ministry spokesman Lu Kang said.

"We believe that insisting on effective implementation of the deal could have served as a very good example for solving other hot international issues," Lu said.

Lu's remarks came after US Secretary of State Mike Pompeo laid out new US strategy on Monday, threatening tough sanctions on Iran and listing 12 demands.

The demands include providing the International Atomic Energy Agency "with unqualified access to all sites throughout the entire country" and ending" its proliferation of ballistic missiles", Pompeo said.

He said the administration of US President Donald Trump prefers to have "a treaty", but will not renegotiate the deal, which was reached in 2015 between Iran and six other countries, including the United States, plus the European Union.

Pompeo's speech came two weeks after Trump announced Washington's withdrawal from the deal and said Washington wants Iran to negotiate a new one.

On Wednesday, Lu urged the continued implementation of the deal and a building of mutual trust to solve other issues that the parties involved are concerned with.

"China urges all relevant parties to take a responsible attitude, eye the long-term perspective and bigger picture and base themselves on reality and reason to continue sticking to the right approach of solving the issue through diplomatic dialogue and manage differences properly," he said.

Pompeo's speech sparked dissatisfaction from Iran and other signatories to the deal.

"All world countries want independence in their decision-making ... and it is not logical that the Americans decide for the world," Iranian President Hassan Rouhani said on Monday.

"Secretary Pompeo's speech has not demonstrated how walking away from the JCPOA (the deal) has made or will make the region safer from the threat of nuclear proliferation or how it puts us in a better position to influence Iran's conduct in areas outside the scope of JCPOA," Federica Mogherini, the EU's foreign policy chief, said in a statement.

French Foreign Minister Jean-Yves Le Drian said on Wednesday the US risks further destabilizing the Middle East, Agence France-Presse reported.

Xinhua contributed to this story.