USA crude settled down $1.67 at $69.06 per barrel and Brent settled down $1.32 at $74.85.
Saudi Arabia has vowed to develop a nuclear arsenal if Iran does as tensions between the Middle Eastern nations escalate. Brent futures were just above $77 per barrel Tuesday and West Texas Intermediate futures settled at $71.14 per barrel. John Kemp is a Reuters market analyst.
In the past, the kingdom has stepped in to fill gaps in global oil supply.
Oil prices are stable because of market stability, he said, because OPEC's goal "is not prices but market stability and lowering storage levels". The JCPOA is working - that is a view shared by our European allies, independent experts, and the current U.S. Secretary of Defense.
"Bahrain reiterates its support for all efforts aimed at making the Middle East free of nuclear weapons and other weapons of mass destruction, stressing its stance towards all measures taken to prevent Iran from obtaining nuclear weapons, to combat its funding and support of extremist militias in the region, and to urge Iran to respect its neighbours' sovereignty and not to interfere in their internal affairs", It said.
Abdulaziz al-Sager, head of the Jeddah-based Gulf Research Centre, said the message was significant in that it reflected Gulf concerns.
Trump's claim that his withdrawal decision from the Iran deal will strengthen his hand in negotiating a better Iran deal is yet to be proven. "The ideal world is one where you can keep the ruble from appreciating, keep the cost down and that would mean a stable price".
Saudi Arabia now pumps around 10 million bpd, but has capacity of around 12 million bpd - a surplus of two million bpd. "With all the US production coming into the system, the market would look forward to a glut".
The EIA on Tuesday raised its forecast for US output in its monthly report to 12 million bpd late next year.
Commenting on the USA withdrawal from the agreement, he said: "The 2015 deal only tackled Iran's nuclear role".
Several refiners in Asia said they were seeking alternatives to Iranian supplies. "The big ones are the likes of Japan and other Asian consumer countries".
OPEC and other major producers, led by Russian Federation, have been cutting 1.8 million barrels per day (MMBPD) of production from the market to help drain the global supply glut and lift crude prices, to a three and a half-year high recently.
Saudi Arabia, the UAE, Bahrain and Egypt imposed a trade and transport boycott on Qatar in June, accusing it of financing militant groups and cosying up to Iran - charges it denies. Its production accounts for about 4 percent of the world's oil supplies. It was also helped by the loss of barrels from Venezuela, which is now producing 1.5 million barrels, well under its quota.
Saudi Arabia said it reaffirmed its support for and welcomes the strategy previously announced by the United States president.
"We believe the nuclear deal was flawed", al-Jubeir said, criticizing portions of the agreement that expire and the fact that its scope is limited to nuclear issues. I think that's a little bit of an exaggeration.
The renewed sanctions, aimed at the heart of the Iranian economy, will impact the country's energy, financial, and petrochemical sector.
"We have managed to put together this new alliance between OPEC and non-OPEC".
"There is likely to be a feeling of jubilation in Riyadh and Abu Dhabi that the Trump administration - or at least the White House - has now come round to their thinking on Iran's threat to regional security". You could have this group continue and it goes into next year...
Jubeir was echoing comments by Saudi Crown Prince Mohammad bin Salman, who said during a visit to the United States in March that Riyadh will be quick to develop nuclear bombs if Iran does so.
The kingdom suffered its first casualty from a missile attack in March when an Egyptian resident of Riyadh was hit by debris from three missiles targeting the capital as part of a wider attack also aimed at Najran, Jizan and Khamis Mushait.
"Until we get to $85 or $90 a barrel, what are they going to do?"
Iran has, according to Politifact, largely complied with the 2015 deal.
Barkindo said the cartel was committed to seeing the agreement through, but he hinted that market conditions could spur a change.
"Once again the bounty of higher prices will be bestowed on Saudi Arabia at the expense of Iran", he said.