Oil futures surged Monday, with global benchmark crude prices scoring their highest settlement in nearly four years and U.S. benchmark crude finishing the session at a more than two-month high.

Major oil producers declined to commit to an additional increase in crude output to address expected supply disruptions at a closely watched producer meeting over the weekend.

November Brent UK:LCOX8 rose $2.40, or nearly 3.1%, to settle at $81.20 a barrel on the ICE Futures Europe exchange, following a weekly advance for crude of 0.9%. Global benchmark oil futures marked the highest settlement Nov. 12, 2014, according to Dow Jones Market data.

November West Texas crude US:CLX8 settled $1.30, or 1.8%, higher at $72.08 a barrel on the New York Mercantile Exchange, following a weekly gain of more 2.6%. Prices, based on the front-month contracts, settled at the highest level since July 10.

A committee made up of some members of the Organization of the Petroleum Exporting Countries and nonmember crude producers, know as the Joint OPEC-non-OPEC Ministerial Monitoring Committee, over the weekend in Algiers delivered no formal plan to boost output to offset an estimated 2 million barrels a day of oil that will be lost due to U.S. sanctions on Iran’s exports set to take effect Nov. 4. The JMMC’s next meeting will be held in Abu Dhabi a week after the oil sanctions kick in.

“I do not influence prices,” Saudi Energy Minister Khalid al-Falih told reporters in Algeria, according to Reuters. The report indicated that no plan was established to lift output, suggesting that the cartel and its members may be willing to let prices run higher.

“Clearly, the biggest oil producer of the OPEC has no interest to disturb the oil equilibrium now,” said Naeem Aslam, chief market analyst with Think Markets, in emailed comments Monday. “Non-OPEC oil producer, Russia also echoed a similar message and made it clear that the country has no interest to play with the oil equation now.”

Oil prices have been on the rise, boosted in part by President Donald Trump’s decision to pull out of the Iran nuclear accord and renew sanctions on the country, which are aimed at sharply curtailing the major producer’s exports.

Already, Iranian exports have fallen by around 500,000 barrels a day between April and August, according to the International Energy Agency.

OPEC and non-OPEC producers had agreed in June to boost production by 1 million barrels a day in an effort to get output nearer to a previously agreed upon ceiling. Headed into the Algiers meeting, there was speculation that an additional output increase of 500,000 barrels a day would be implemented to address shrinking supplies from Iran.

Elevated crude prices have grabbed the attention of Trump, who tweeted last week that OPEC “must get prices down now.”

According to The Wall Street Journal, energy ministers in Algiers were unable to strike an accord on how best to allocate any increases in production to help address Iranian shortfalls.

Talks also were complicated by the inequalities inherent in OPEC, notably, between producers, like Saudi Arabia and Russia, who can easily ramp up output, and smaller nations that would benefit from higher prices but can’t easily boost production levels.

Ultimately, the weekend’s convention in Algeria concluded with producers saying that they would adhere to production quotas to which they agreed in late 2016.

In any event, some market participants doubt that OPEC and non-OPEC members would be able to keep prices in check.

“The market does not have the supply response for a potential disappearance of 2 million barrels a day in the fourth quarter,” said Daniel Jaeggi, co-founder of Mercuria Energy Group Ltd., in a recent speech at the S&P Global Platts Asia Pacific Petroleum Conference.

“In my view, that makes it conceivable to see a price spike north of $100 a barrel.” Bloomberg News reported.

Petroleum-product prices traded on Nymex Monday also saw broad gains. October gasoline US:RBV8 added 1.9% to $2.055 a gallon and October heating oil US:HOV8 rose 2.7% to $2.286 a gallon.

October natural gas US:NGV18, which expires Wednesday, settled at $3.038 per million British thermal units, up nearly 2.1%. Prices settled above $3 for the first time this year.

Total U.S. stocks of natural gas “remain well below normal levels, with the deficit expected to widen over the next couple of weeks,” said Robbie Fraser, commodity analyst at Schneider Electric.