Following a 4% surge on Wednesday, oil prices advanced by another 1.6% in European trade early on Thursday to send Brent to above $71.50, the highest level in six months, as concerns about a U.S. military campaign in Iran intensified.

The international benchmark, Brent Crude, was up by 1.71% at $71.55 in morning trade in Europe, as the U.S.-Iran talks appear to make no headway, while the U.S. is amassing military forces near the Persian Gulf.

The U.S. benchmark oil prices, WTI Crude, also jumped to trade at $66.37 per barrel, up by 1.83% on the day, following the 4% surge at Wednesday’s settlement.

The U.S. Administration has warned Iran that it would be “very wise” to make a deal as diplomatic efforts and talks continue.

On Wednesday, Axios reported that the U.S. is moving closer to a war with Iran. A campaign in Iran would be nothing like the Venezuela blitz and could involve “a massive, weeks-long campaign,” Axios reported, citing sources.

U.S. President Donald Trump has not yet made a final decision about a possible military intervention, sources with knowledge of the discussions among top U.S. national security officials told CBS News. But the President has discussed options, including a strike that could be ordered as soon as this coming Saturday, according to the sources.

“For oil markets, the concern is clearly what action would mean not only for Iranian oil supply, but also broader Persian Gulf oil flows, given the risk of disruption to shipments through the Strait of Hormuz,” ING strategists Warren Patterson and Ewa Manthey wrote in a Thursday note.

Adding to the difficult U.S.-Iran talks, the Russia-Ukraine talks in Geneva also broke down without any breakthrough and pushed oil prices higher.

Moreover, the shape of the ICE Brent futures curve suggests that the oil market is “tighter than what many analysts have been expecting, including us,” ING’s strategists said, noting that many buyers aren’t touching large volumes of sanctioned barrels, which is tightening supply.

By Tsvetana Paraskova for Oilprice.com

More Top Reads From Oilprice.com

U.S. Attacks Alleged Drug Boats as Venezuela Oil Crackdown Escalates

Ovintiv To Sell Anadarko Energy Assets In $3 Billion Deal

Libya Awards Fuel Supply Deals To Western Firms, Aims To Cut Russian Imports

Oilprice Intelligence brings you the signals before they become front-page news. This is the same expert analysis read by veteran traders and political advisors. Get it free, twice a week, and you'll always know why the market is moving before everyone else.

You get the geopolitical intelligence, the hidden inventory data, and the market whispers that move billions - and we'll send you $389 in premium energy intelligence, on us, just for subscribing. Join 400,000+ readers today. Get access immediately by clicking here.