President Donald Trump has urged Saudi Arabia to increase its oil production to combat the rising cost of fuel.
He tweeted that he had asked King Salman of Saudi Arabia to raise oil output by up to two million barrels a day.
President Trump said the move was needed due to “turmoil and dysfunction in Iran and Venezuela”.
Oil prices rose last week, partly due to US plans to re-impose sanctions on Iran, a major oil producer.
The OPEC group agreed to increase output, as did Russia, but this failed to reassure markets.
The Saudi Press Agency confirmed that President Trump and King Salman had spoken by phone, giving few details. According to the news agency, they had discussed the need to “preserve the stability of the oil market”.
However, the statement did not confirm that Saudi Arabia had agreed to the two million barrels a day figure.
Saudi Arabia is the world’s biggest exporter of oil and produced about 10 million barrels a day in May. The country is reported to have between 1.5 million and two million barrels a day of spare capacity – but experts told The Wall Street Journal it might not be keen to meet the president’s request.
A Saudi official told the WSJ: “Saudi Arabia does not really like going beyond 11 million barrels a day and has no intention of expanding its current production capacity. It is expensive.”
Donald Trump has repeatedly criticized OPEC even though US ally Saudi Arabia is a core member.
On April 20, President Trump tweeted that oil prices were “artificially very high”, saying this was “no good” and “will not be accepted!”
Iran, another OPEC member, has accused Donald Trump of trying to politicize the group and has blamed Riyadh for doing his bidding.
On June 30, Iranian Supreme Leader Ayatollah Ali Khamenei said the US was trying to drive a wedge between Iranians and their government using “economic pressure”.
He cautioned on his website: “Six US presidents before him tried this and had to give up.”
The value of Iranian currency, the rial, has tumbled since the US backed out of the Iran nuclear deal in May.
Earlier this week, thousands of traders at Tehran’s Grand Bazaar marched in protest against rising prices and the plummeting value of the rial. It was the biggest protest Tehran has seen since 2012.