Iranian Oil Minister Bijan Zanganeh talks to journalists at the beginning of an OPEC meeting in Vienna, Austria, Nov. 30, 2017. Photo: Reuters / Heinz-Peter Bader / File.

Iran will respond if other OPEC members threaten its interests, Oil Minister Bijan Zanganeh said on Thursday amid rising pressures from Washington to bring Iranian crude sales to zero with the help of Tehran’s regional rivals.

The United States has demanded that buyers of Iranian oil stop purchases by the start of May or face sanctions, ending six months of waivers that had allowed OPEC member Iran’s eight top customers, most of them in Asia, to import limited volumes.

Saudi Arabia has welcomed the US move to end all Iran sanction waivers and has said it is ready to meet oil consumers’ demand by replacing supplies from Tehran.

After a meeting with OPEC Secretary-General Mohammad Barkindo in Tehran, Zanganeh warned that OPEC might “collapse” because of “unilateral actions” by some members, in an obvious reference to Saudi Arabia.

“Iran is a member of OPEC because of its interests, and if other members of OPEC seek to threaten Iran or endanger its interests, Iran will not remain silent,” Zanganeh was quoted as saying by the oil ministry’s news agency, SHANA.

Earlier in the day, Barkindo said at an oil and gas exhibition in the Iranian capital that “OPEC tries to depoliticize oil,” Iran’s Oil Ministry reported on Twitter.

“I have told my colleagues at OPEC that you must leave your passports home when coming to this organization,” Barkindo was quoted as saying.

Asked by a reporter if it was technically possible to implement US sanctions against Tehran, Barkindo said: “It is impossible to eliminate Iranian oil from the market.”

Echoing Zanganeh’s comments, Barkindo said “We have faced troubles in the OPEC in the last 60 years, but we have resolved them by unity.”

“What is happening in Iran, Venezuela or Libya has an impact on all the market and the energy sector.”