Mohammad Javad Zarif will later fly to Moscow and Brussels to consult with the remaining signatories to the 2015 agreement denounced by President Donald Trump.
Washington's decision to withdraw from the agreement and reimpose sanctions infuriated its allies in Europe as well as China and Russia.
China was one of the six powers -- with the United States, Russia, France, the UK and Germany -- that signed the historic pact which saw sanctions lifted in return for the commitment by Tehran not to acquire nuclear weapons.
As he arrived in Beijing, Zarif said, "we will discuss the decision that Iran should take", according to the semi-official ISNA news agency.
He added: "As the president of the republic has said, we are ready for all option(s). If the nuclear deal is to continue, the interests of the people of Iran must be assured."
Zarif, who is set to hold talks with his opposite number Wang Yi, hailed Tehran's relations with Beijing, ISNA reported.
"We have had good relations with China before and since the deal," he said.
"China is by far the first economic partner of Iran. We are certain that today China is by our side."
Tehran's chief diplomat embarked on the tour as regional tensions spiked just days after unprecedented Israeli strikes in Syria which a monitor said killed at least 11 Iranian fighters, triggering fears of a broader conflict between the two arch-enemies.
Before leaving, Zarif published a government statement on his Twitter page, slamming Trump's "extremist administration" for abandoning "an accord recognised as a victory of diplomacy by the international community".
