Croft thinks a military conflict has already commenced: File Image/Pixabay

U.S. president Donald Trump stating he will decide whether to attack Iran in the next 10 days caused oil prices on Thursday to rise to a six-month high.

Brent settled up $1.31 at $71.66 per barrel, and West Texas Intermediate settled up $1.24 at $66.43 per barrel.

As Trump told media "We have to make a meaningful deal, otherwise bad things happen," the USS Abraham Lincoln aircraft carrier was stationed in the Middle East and the USS Gerald Ford was en route.

RBC Capital Markets analysts including Helima Croft wrote in a note, "The massive buildup of U.S. military assets in the region as well as the recent Iranian naval exercise in the Strait of Hormuz seem to suggest that the launch sequence for a second military conflict has commenced."

Meanwhile, testing the persistent worry that demand isn't matching output in the oil market were figures from the Energy Information Administration, which showed that U.S. crude stockpiles fell by 9 million barrels last week, the biggest drop since early September; oil product inventories also declined across the board.

This was contrary to expectations for a crude stockpile rise of 2.1 million barrels, and Phil Flynn, senior market analyst at Price Future Group Inc., credited the drawdowns to winter storms, adding, "We have a solid market with solid demand and that should give [prices] support until the end of the day."

Patrick de Haan, the head of petroleum analysis at GasBuddy, stated on Thursday that the current oil price increase may combine with a seasonal price hike for gasoline set to take effect within weeks, due to increased travel during the warmer spring weather; however, he added that the likely uptick will  "not necessarily cause a 2022-era spike."

Prices at the pump are said to be one major reason why Trump, mindful of consumer ire if they escalate unduly, may decide not to attack Iran.