Oil futures settled back under $60 a barrel on Thursday, with traders increasingly worried about how much oil Iran can add to the global market should sanctions be lifted as part of a deal with world powers over its nuclear program.

June crude fell $1.99, or 3.3%, to settle at $58.94 a barrel on the New York Mercantile Exchange. Prices had settled near $61 Wednesday at their highest level of the year. Brent crude for June delivery on London’s ICE Futures exchange settled lower by $2.23, or 3.3%, lower at $65.54 a barrel. Iran is “talking big,” said Phil Flynn, senior market analyst at the Price Futures Group.

Iran produces about 2.7 million barrels a day, but Oil Minister Bijan Zangeneh said Thursday that if sanctions are lifted this year, the country could be pumping 5.7 million barrels a day by 2018, according to The Wall Street Journal. “Obviously, that won’t happen soon,” said Flynn. Iran and six world powers must reach a final agreement by June 30. Separately, AFP reported, citing comments from top government officials in Tehran, that a nuclear agreement would allow Iran to become the No. 1 energy player in the Middle East. Naeem Aslam, chief market analyst at AvaTrade, said he believes the news on Iran “is nothing but noise as it will take much longer time for Iranian oil to come on the market.”

For now, traders are concerned that U.S. shale oil production will begin to recover, analysts said.

Prices are still down by about 40% from last summer. But on Wednesday, Nymex oil settled at its highest level since December after government data showed that crude inventories unexpectedly fell for the first time in 17 weeks. Jason Rotman, president of Lido Isle Advisors said the market is “still well supplied,” and any moves into the low $60s for West Texas Intermediate oil “will be looked at as major selling opportunities.” He thinks oil is headed back down to $56.

Traders expect the monthly jobs report Friday to offer clues on the timing of the Federal Reserve’s next rate hike. A rate hike could lead to a stronger dollar and bring down dollar-denominated oil prices.