Russia will stand by the Iran nuclear deal and develop closer ties with Iran if US President Donald Trump withdraws from the agreement on May 12, a senior Russian official said yesterday.

Vladimir Yermakov, Director General of the Department for Non-Proliferation and Arms Control at Russia's Foreign Ministry, told reporters that a US withdrawal from the 2015 accord known as the JCPOA did not necessarily mean the end ofthe deal.

"It might even be easier for us on the economic front, because we won't have any limits on economic cooperation with Iran. We would develop bilateral relations in all areas - energy, transport, high tech, medicine," he said.

Trump, a long-time critic of the deal struck by major world powers, has threatened to pull out unless a follow-on agreement is reached to fix what he calls its "flaws."

"If the United States breaks an international agreement backed by UN Security Council resolutions, it will be the United States that should suffer the consequences. Neither Iran nor China nor Russia nor the European states should lose out," Yermakov said.

If the United States pulled out, there was no question of discussing new UNSC sanctions on Iran, he added.