U.S. stock-index futures were little changed on Sunday, as new threats of escalation from both President Donald Trump and Iran threatened to intensify the conflict roiling the Persian Gulf region.

Over the weekend, Trump threatened to "obliterate" key Iranian power plants if the Strait of Hormuz is not reopened to shipping traffic by late Monday. That led Iran's foreign minister to threaten attacks against critical infrastructure used by Israel, the U.S. and Gulf states, including power plants, telecommunications systems and water desalination facilities.

After shaking off sharp initial losses, Dow Jones Industrial Average futures fell 0.1%, while S&P 500 futures fell 0.2% and Nasdaq-100 futures were down 0.3%.

West Texas Intermediate crude futures briefly topped $100 a barrel on Sunday, but were last around $98, amid fears that oil prices could rise as high a $175 a barrel, which would likely push the U.S. into a recession. Brent crude, the global benchmark, remained well above $100 a barrel. The vital Strait of Hormuz remains effectively closed to shipping, bottling hundreds of tankers and other ships in the Persian Gulf. More than 20 ships have been hit so far, according to the U.K. Maritime Trade Operations Center.

Bitcoin sank over the weekend, and was last trading above $68,000. Gold prices, coming off their worst weekly percentage drop in more than 14 years, fell again on Sunday, while silver prices tumbled as well.

Last week, the three major U.S. stock indexes suffered their fourth straight week of losses. The Dow fell 2.1% for the week, while the Nasdaq slid 2.1% and the S&P 500 dropped 1.9%, according to FactSet data. That put the indexes on the brink of a correction, defined as a decline of at least 10% from a recent high. The S&P 500 is down 6.8% from its January peak, while the Dow is off 9.2% and the Nasdaq has slumped 9.6%. On Friday, the small-cap Russell 2000 closed in correction territory.

"Every tick higher in energy is being translated directly into inflation expectations, policy assumptions, and risk appetite, and that transmission mechanism is not subtle. It is blunt force," Stephen Innes, managing partner at SPI Asset Management, wrote in a weekend note.

Investors are becoming more worried that the war with Iran will cause lasting economic damage as it continues. While the "TACO trade" - betting that "Trump Always Chickens Out" - has paid off for buy-the-dip investors over the past year, this time seems different, as the attacks on Iran have set off a complicated global chain of events that looks increasingly difficult to stop.

"The markets may be in for a rude awakening when they realize that Trump doesn't control the outcome of this conflict," Nic Puckrin, co-founder and CEO of digital-asset analysis platform Coin Bureau, said in a weekend note. "With no easy resolution to the Iran war in sight, risks are to the upside that it will drag on. And the longer oil stays above $100, the longer it will take to undo the damage."

Meanwhile, gas prices in the U.S. are approaching $4 a gallon. On Friday, United Airlines CEO Scott Kirby said the airline will cut some routes as it braces for higher jet-fuel costs, saying the company expects crude prices to stay above $100 a barrel through 2027.

Treasury Secretary Scott Bessent said Sunday he doesn't know how long the higher fuel prices will last, but that paying more is an acceptable tradeoff for "peace in the Middle East."

"Prices will come off on the other side," Bessent said on NBC's "Meet the Press" on Sunday. "There is no prosperity without security."

Bessent also defended Trump administration moves to lift some sanctions on Iranian and Russian oil, and refused to rule out the use of U.S. ground troops against Iran.

On that same show, Sen. Chris Murphy, the Connecticut Democrat, said the Trump administration "has totally lost touch with reality. This war is spinning out of control."

"There's no end in sight," Murphy said. "The secretary of Treasury just said we're going to escalate in order to de-escalate - it's like they've never read a history book... The only way to lower energy prices is to end this war."