New York, Aug 29 (IANS): It will be a "very big mistake" for the US to withdraw from the 2015 nuclear deal with Iran, a former official under the Barack Obama administration has said.

"That would be a very big mistake to withdraw from the pact because there's no evidence that Iran is violating the agreement, the JCPOA (Joint Comprehensive Plan of Action)," said Robert Hormats, former Under Secretary of State for Economic Growth, Energy, and the Environment, in a recent interview with Xinhua.

If Washington does pull out of the deal even though there is no evidence of Iranian violation, Americans would be "isolated from our own allies ... American companies would suffer ... American influence in the region would suffer," noted Hormats, who is also vice chairman of Kissinger Associates, a New York-based international consulting firm.

"What happens if they (Iranians) resume their nuclear program (following the US pulling out of the deal), which moves them further toward building a nuclear weapon," Hormarts said. "To me it would be a huge miscalculation, and enormously bad judgment on the part of Washington to do this."

After years of tension with the West, Iran struck a deal with the five world powers of Britain, China, France, Russia and the United States plus Germany in July 2015, under which Iran agreed to limit its uranium-enrichment activities in return for the lifting of western and international sanctions.

The international agreement is facing a serious threat of collapse as tensions mounted between Washington and Tehran recently.

US President Donald Trump, who during his election campaign had called the Iranian nuclear deal a "disaster" and "the worst deal ever negotiated," approved new sanctions on Tehran this month for its missile programme.

Iran accused Washington of breaching the 2015 agreement. But Washington argued that the sanctions were not related to the nuclear deal.

Iranian President Hassan Rouhani has warned that his country could pull out of the deal should Washington impose any new sanctions. Iran's atomic chief Ali Akbar Salehi said that his country could resume production of highly enriched uranium within five days if the 2015 deal is revoked.