Oil retreated as the dollar strengthened, erasing earlier gains from growing speculation that President Trump may reimpose sanctions on Iranian crude exports.

Futures in New York dropped as much as 1.1 percent after rising 0.5 percent earlier. Israeli Prime Minister Benjamin Netanyahu said his country has documents that prove Iran had a program to build atomic bombs. That’s raising concern Trump may pull the U.S. out of a nuclear accord between Iran and world powers, a move that energy consultant FGE says could cut the Persian Gulf nation’s 2019 oil exports by 700,000 barrels a day.

Oil rallied last month to the highest level in more than three years amid concern that a U.S. withdrawal from the nuclear deal would result in fresh export curbs, as well as issues including the conflict in Syria and tensions between Saudi Arabia and Iran-backed rebels in Yemen. At the same time, production cuts led by the Organization of Petroleum Exporting Countries have continued to tighten global markets, despite record-setting U.S. output.

“Uncertainty as to the continuation of the current nuclear deal between Iran and six world powers continues to loom,” said Michael Poulsen, an analyst at Global Risk Management Ltd.

West Texas Intermediate crude for June delivery traded at $67.95 a barrel on the New York Mercantile Exchange, down 62 cents, at 10:52 a.m. London time. The contract advanced 0.7 percent on Monday. Total volume traded Tuesday was about 5 percent below the 100-day average.

Brent crude for July settlement fell 53 cents to $74.16 a barrel on the London-based ICE Futures Europe exchange. The June contract expired Monday up 53 cents, or 0.7 percent, at $75.17. The global benchmark crude traded at a $6.28 premium to July WTI.

Trading on the Shanghai International Energy Exchange was closed for a Chinese public holiday.

Stronger Dollar

Gains in the dollar helped to push crude prices down. The greenback strengthened 0.4 percent to $1.2036 against the euro, blunting the appeal of commodities priced in the U.S. currency.

Netanyahu said Israel uncovered 55,000 pages of material on an Iranian weapons program that operated between 1999 and 2003, and that the nuclear work continued after it was subsumed under a different guise. Iran’s foreign minister, Mohammad Javad Zarif, called Netanyahu’s allegations lies “already dealt with” by the International Atomic Energy Agency.

Netanyahu spoke less than two weeks before Trump is due to decide whether the U.S. will pull out of the international agreement that curbed Iran’s nuclear program in exchange for sanctions relief.

May Deadline

The European Union’s foreign minister, Federica Mogherini, said the evidence so far fails to show non-compliance with the nuclear agreement. In remarks in Washington, the American president left open the possibility of negotiating a new accord but hinted the U.S. would quit the deal by May 12, the deadline he’s set for a decision.

FGE Chairman Fereidun Fesharaki said Trump is likely to restore sanctions on Iran, meaning buyers would have to cut their crude purchases from the country in 180 days. The nation’s exports could drop by 200,000 to 500,000 barrels a day this year, leading to higher oil prices, he said.

In the U.S., crude stockpiles probably added 900,000 barrels last week, according to a Bloomberg survey. If confirmed by government data on Wednesday, that would be the second consecutive weekly gain in inventories.

Other oil-market news:

• U.S. imports of crude from OPEC countries fell 9.8 percent in February to 2.43 million barrels a day, the lowest since January 2015, according to the Energy Information Administration.
• Oil production in Texas jumped almost 21 percent in February from a year earlier to a record 4.01 million barrels a day, according to the EIA.
• U.S. imports of gasoline from Europe last week climbed to the highest since at least December 2016.