Brent crude oil prices rose to their highest since November 2014 on Monday ahead of U.S. sanctions against Iran, the third-largest producer in the Organization of the Petroleum Exporting Countries (OPEC), that kick in next month.

Benchmark Brent crude oil futures LCOc1 rose to as much as $83.27 a barrel and were at $83.21 at 0339 GMT, up 48 cents, or 0.6 percent from their last close.

U.S. West Texas Intermediate (WTI) crude futures CLc1 were up 32 cents, or 0.4 percent, at $73.57 a barrel.

WTI prices were supported by a report on Friday of a stagnant rig count in the United States, which points to a slowdown in U.S. crude production C-OUT-T-EIA, which now rivals top producers Russia and Saudi Arabia.

Brent was pushed up by looming sanctions against Iran, which will start targeting its oil sector from Nov. 4.

ANZ bank said on Monday that “the market is eyeing oil prices at $100 per barrel”.

In a sign that the financial market is positioning itself for further price rises, hedge funds increased their bullish wagers on U.S. crude in the week to Sept. 25, data from the U.S. Commodity Futures Trading Commission (CFTC) showed on Friday, increasing futures and options positions in New York and London by 3,728 contracts to 346,566 during the period.

In a further sign of the impact that the U.S. sanctions on Iran will have on the market, China’s Sinopec said it is halving loadings of Iranian crude oil this month. China is the biggest buyer of Iranian oil.

“If Chinese refiners do comply with U.S. sanctions more fully than expected, then the market balance is likely to tighten even more aggressively,” Edward Bell, commodity analyst at Emirates NBD bank wrote in a note published on Sunday.

U.S. President Donald Trump called Saudi Arabia’s King Salman on Saturday, discussing ways to maintain sufficient supply once Iran’s exports are hit by sanctions.

“Until sizable supply is offered up by OPEC, ultimately traders will continue to push the envelope even more,” said Stephen Innes, head of trading for Asia-Pacific at futures brokerage Oanda in Singapore.

“Even if they (Saudi Arabia) wanted to bend to President Trump’s wishes, how much spare capacity does the Kingdom have?” asked Innes.

“We’re going to find out very soon as approximately 1.5 million barrels (per day) of Iranian oil is effectively going offline on Nov. 4. If the market senses that Saudi Arabia capacity is tapped out at 10.5 million bpd ... oil prices will rocket higher with the flashy $100 per barrel price tag indeed a reasonable sounding target,” Innes said.