China said on Wednesday it "regrets" the decision by the United States to pull out of the Iran nuclear deal, and Beijing will continue its commitment to safeguard and implement the deal, the Foreign Ministry said.

The agreement, known as Joint Comprehensive Plan of Action, was reached among multiple parties and approved by the United Nations Security Council, Foreign Ministry spokesman Geng Shuang said in a daily news conference. All parties involved should carry it out with seriousness and safeguard its integrity, Geng said.

Doing so will help maintain the international nonproliferation regime, promote peace and stability in the Middle East and serve as an example of solving hot spot issues through political means, Geng said.

"China calls on all parties to ... stick to the direction of a political and diplomatic settlement, handle their differences properly and come back to the right track of implementing the deal as soon as possible," Geng said. China will maintain talks with all parties, he said.

US President Donald Trump announced in a speech on Tuesday that his country will withdraw from the deal and reinstate its sanctions on Iran, and that Iran is "going to want to make a new and lasting deal".

Trump's announcement has also sparked concerns and opposition from the other parties to the deal.

In a joint statement issued by the British Prime Minister's office, the leaders of France, Germany and Britain said they took note of Trump's decision "with regret and concern".

The deal was struck between Iran and the US, Britain, France, Russia and China, plus Germany and the European Union, in Vienna in 2015.

The deal asks Iran to limit its nuclear program in return for the lifting of economic sanctions the international community imposed on the country.

In a statement on Tuesday, the Russian Foreign Ministry said it was "deeply disappointed by the decision of US President Donald Trump to unilaterally refuse to carry out commitments under the Joint Comprehensive Plan of Action," according to AFP.

Iran President Hassan Rouhani said on Tuesday that the Islamic Republic will remain in the nuclear deal with other signatories without the US.

"From this time on, the nuclear deal is an accord between Iran and five countries," Rouhani said in live speech broadcast from state TV.

Ruan Zongze, vice-president of the China Institute of International Studies, said the US is sending the "wrong signals" by quitting the Iran nuclear deal, as such moves will undermine future efforts to solve issues in the Middle East through talks.

Emma Ashford, a research fellow with the Cato Institute, a think tank in Washington, said in an analysis on Tuesday that by leaving the nuclear deal without offering any clear strategy or plan for an alternative, "Trump is opening Pandora's box, increasing the risks of escalation and bringing us gradually closer to conflict with Iran."

Xinhua contributed to this story.