Foreign Minister Mohammad Javad Zarif has embarked on a whirlwind diplomatic tour to gauge international readiness to guarantee Iran's interests if it decides to remain in a nuclear deal after US withdrawal.

Zarif departed for Beijing in the early hours of Sunday before heading to Moscow and Brussels to hold meetings with the remaining parties to the 2015 agreement, his spokesman said.

The trip comes less than a week after President Donald Trump announced that the US was walking away from the Joint Comprehensive Plan of Action (JCPOA) which he described as a horrible deal.

Trump also said he would reinstate US nuclear sanctions on Iran and impose "the highest level" of economic bans on the Islamic Republic.

Iran has said it would remain in the JCPOA for now, pending negotiations with the other signatories in the coming weeks before making a final decision on its future role in the agreement.

Zarif began the tour on President Hassan Rouhani's order to sound out Europe and other parties to the JCPOA about the possibility of keeping the deal in place. Iran wants the Europeans to give it clear-cut guarantees about fulfilling their obligations if Tehran remains in the deal.

"The European countries should give us guarantees that in spite of the US withdrawal from the JCPOA, the interests of the Iranian nation will still be protected," IRNA quoted Zarif as telling reporters upon arrival in Beijing.

In Brussels, Zarif will attend a meeting with his French, German and British counterparts as well as EU foreign policy chief Federica Mogherini.

"We are waiting now for how the decision-makers in the European Union will react. If the EU leans towards accommodating the US, all the progress we have made since 2015 will be lost," Agence France-Presse said Sunday, citing a Western trade diplomat in Tehran who spoke on condition of anonymity.

Before leaving, Zarif published a government statement on his Twitter page, slamming the "extremist administration" of President Trump for abandoning "an accord recognized as a victory of diplomacy by the international community."

It reiterated that Iran was preparing to resume "industrial-scale" uranium enrichment "without any restrictions" unless Europe provided solid guarantees that it could maintain trade ties despite renewed US sanctions.

While the remaining JCPOA parties are scrambling to save the deal, Israel has played a second fiddle to the US bid to wreck it.

Israeli warplanes hit dozens of military targets in Syria early Thursday, claiming that they were in response to an Iranian rocket attack from the Syrian territory.

Syrian officials rejected the Israeli claim that the assault had been directed at Iranian infrastructure. "Israel’s claim that it had targeted Iranian assets in Syria has no substance," Syrian Ambassador to China Imad Moustapha said on Friday.

Traditionally, Iranian officials do not respond to Israeli claims, saying they do not merit an answer.

Political observers point to the timing of the Israeli attack which came right after Trump's withdrawal from the JCPOA, saying it was aimed at complicating the diplomatic push to keep the nuclear deal in one piece.