"The JCPOA is effective in petroleum industry as long as we will be able to sell our oil and keep our market share, receive our oil money without any problem, purchase our necessary oil equipment and finance our projects," Amir-Hossein Zamani-Nia said, referring to the official appellation of the agreement – Joint Comprehensive Plan of Action (JCPOA).

He said that Iran's petroleum industry would not return to the pre-sanctions era in 2013, "no matter what decision Mr Trump would take tonight."

US President Donald Trump is expected to announce his decision about remaining in or quitting the JCPOA. Iran was under tough US and European sanctions before 2013, chipping away at its oil exports.

"Under no circumstances, will we return to the sanctions era; however, we do not welcome problems, but we will overcome them," said Zamani-Nia.

"The Iranian oil and gas industry has been faced with myriads challenges throughout its 110-year history, and tonight's Trump decision is one of problems which Iran's petroleum industry has learnt how to deal with."