US President Donald Trump has threatened to pull out of the Iran deal by not extending sanctions waivers when they expire on May 12 unless European signatories of the accord fix what he calls its "flaws".

"They cannot stop Iran. Our oil industry's development will continue even if new sanctions are imposed on Iran," SHANA quoted Gholamreza Manouchehri, deputy head of the National Iranian Oil Company, as saying.

Sanctions imposed on Iran in early 2012 by the United States and European Union over its nuclear programme cut Iran's crude exports from a peak of 2.5 million barrels per day (bpd) before the sanctions to a little more than 1 million bpd.

But Iran re-emerged as a major oil exporter in January 2016 when international sanctions were suspended in return for curbs on Iran's nuclear programme.

Deputy oil minister Amirhossein Zamaninia also said that Iran considered the deal alive "if we can continue to sell our oil and its products", even if the United States pulls out.

"Also, we should be able to maintain Iran's oil market, receive our oil money and secure foreign investment in our oil industry," he added.

Iran says it aims to raise its crude oil production capacity to 4.7 million bpd within the next four years, though exports might be disrupted if Trump refuses to renew Iran's sanctions waivers next week.

The Organization of the Petroleum Exporting Countries (OPEC), Russia and several other producers began to reduce oil output in January 2017 in an attempt to erase a supply glut and prop up prices. They have extended the pact until December 2018 and meet in June to review policy.

"We back OPEC's decisions under normal circumstances ... But Iran always gives priority to its own interests ... whoever produces more oil has more power in the market," Zamaninia said.

Iran's regional rival Saudi Arabia, meanwhilehas shown a willingness to keep tightening crude markets.

The world's largest crude exporter has consistently opposed Iran's nuclear deal, fearing that it will strengthen Iran economically and allow it to increase funding for proxy conflicts in Lebanon, Syria, Iraq and Yemen.

"Saudi officials want to limit Iran's oil market ... This is a fight over controlling the crude market," Zamaninia said.