U.S. oil futures turned lower Tuesday, as traders bet that the departure of U.S. National Security Adviser John Bolton will ease tensions with Iran, potentially leading to the lifting of sanctions, which could put more oil on the market.

President Donald Trump said over Twitter he’d told Bolton he was “no longer needed at the White House” and that Bolton resigned Tuesday morning.

“Bolton is a known hawk on Iran and the market is assuming that opens the door for talks with Iran,” and possibly, “a lifting of sanctions,” said Phil Flynn, senior market analyst at Price Futures Group.

Meanwhile, in a monthly report, the Energy Information Administration significantly cut its U.S. and global benchmark crude-price for this year in next, contributing to losses for U.S. oil prices and weakness in Brent crude.

West Texas Intermediate crude for October delivery CLV19, +0.19%  on the New York Mercantile Exchange fell by 14 cents, or 0.2%, to $57.71 a barrel—off an earlier high of $58.76. November Brent crude BRNX19, +0.53%, the global benchmark, was up 11 cents, or 0.2%, at $62.70 a barrel on ICE Futures Europe, pulling back from an earlier high of $63.78.

Both benchmarks on Monday saw their highest settlements since July 31, according to Dow Jones Market Data. They traded higher early Tuesday, buoyed by prospects for continued production curbs by the Organization of the Petroleum Exporting Countries and its allies.

That upbeat tone was tied in large part to remarks by Prince Abdulaziz bin Salman, who was named Saudi Arabia’s energy minister over the weekend, and affirmed a commitment to production cuts by OPEC and its allies, a grouping known as OPEC+. The oil cartel meets Thursday this week in Abu Dhabi to assess production levels.

Prices also found some support Tuesday after Amin Nasser, chief executive officer of Saudi Arabia’s state-owned oil company, Saudi Aramco, reportedly said his company’s IPO will list locally very soon. “Investors appear to have taken this comment, along with the appointment of a new Saudi Energy Minister…as giving Saudi Arabia extra motivation to at least maintain or preferably push up oil prices in the near term,” said Colin Cieszynski, chief market strategist at SIA Wealth Management Inc.

“Initially, 1% of [Saudi Aramco’s] shares are to be listed on the country’s own exchange. With a targeted market valuation of $2 trillion, $20 billion would thus need to be drummed up from potential investors — which seems ambitious at the current oil prices,” wrote analysts at Commerzbank, in a note. “Saudi Arabia is therefore likely to be very interested in pushing oil prices up further. The only way to reach this goal is to continue exceeding the agreed production cuts.”

Read: As market welcomes new Saudi oil minister, analyst touts Prince Abdulaziz as ‘master’ of OPEC politics

In the short term, the appointment of the new minister is “unclear,” said Chris Midgley, global head of analytics, S&P Global Platts. “General sentiment would be for a concerted effort to provide price support and see if he can be more successful” than the former minister Khalid al Falih.

Looking ahead, monthly oil reports from OPEC and the International Energy Agency will be released later this week.

Weekly updates on petroleum supplies will be issued by the American Petroleum Institute late Tuesday, with official government EIA figures out Wednesday.

The EIA data are expected to show crude inventories down by 3.6 million barrels last week, according to a survey of analysts polled by S&P Global Platts. Gasoline supplies are forecast to fall by 1.4 million barrels, while distillate stockpiles are seen higher by 220,000 barrels.

In other energy trading, October gasoline RBV19, +0.35%  rose 0.05% to $1.5853 a gallon, while October heating oil HOV19, +0.75%  gained 0.6% to $1.9385 a gallon.

October natural-gas futures NGV19, +0.43%  were up 0.3% at $1.593 per million British thermal units.