The leader of Saudi Arabia, OPEC's biggest member, has assured Trump that the kingdom can raise oil production if needed and that the country has 2 million barrels per day of spare capacity that could be deployed to help cool oil prices to compensate for falling output in Venezuela and Iran.

Trump has been complaining about OPEC at the same time that Washington is piling pressure on its European allies to stop buying Iranian oil.

His tweets about OPEC and oil prices have been seen as counterproductive though, more likely to worry the market and put upward pressure on prices than reassure it.

Trump’s interventions with tweets “unsettle” the market and appear to have pushed prices up, Standard Chartered energy analyst Emily Ashford and head of commodities research Paul Horsnell wrote in a note on Tuesday. With oil prices rising ahead of the midterm elections, Trump had before this latest post tweeted his frustration three times to no avail.

“US oil diplomacy has at points in the past been highly successful in calming oil markets, and it has generally been more successful the quieter it has been,” the analysts wrote.