Iran’s oil minister on Thursday predicted a painful time ahead for international oil customers as U.S. sanctions take hold, saying waivers that the Trump administration granted to eight major oil-importing countries are not enough for market demands.

Iranian state TV quoted the minster, Bijan Zanganeh, as saying he sees the months ahead as “painful months for oil consumers.”

Zanganeh claimed the Trump administration may have been able to “superficially” bring fuel prices down ahead of the U.S. midterm elections this week but that there’s bound to be a hike in prices in the future.

The United States on Monday re-imposed oil and banking sanctions on Iran that where lifted under the 2015 nuclear deal but granted waivers to eight major importers to continue buying Iranian petroleum products without penalty for another six months.

Also Thursday, Iran’s representative to OPEC, Hossein Kazempour Ardebili, claimed that Russia and Saudi Arabia were helping Trump by increasing their own production to keep oil prices low. Trump repeatedly has asked oil producers to pump more crude to lower prices.

The latest batch of U.S. sanctions severely impacts Iran’s oil industry, the major source of the country’s foreign revenue. Tehran worries OPEC and non-OPEC countries such as Russia will increase their production to fill the gap in response.

On Tuesday, Zanganeh, the oil minister, wrote a letter to the OPEC chief, asking that the so-called Joint Ministerial Monitoring Committee — which consists of all OPEC and non-OPEC countries —some members of the committee “openly” take side with the United States on the matter of sanctions on Iran.

The committee is due to hold a meeting next week in Abu Dhabi, the capital of the United Arab Emirates, an ally of Iran’s regional rival Saudi Arabia.

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