Washington DC - President Donald Trump struggled to defend his war on Iran as oil prices surged above $100 a barrel for the first time in nearly four years on Sunday.

Both crude oil benchmarks, the West Texas Intermediate (WTI) and Brent, jumped by over 15% as markets opened Sunday evening, touching levels not seen since the early months of Russia's 2022 invasion of Ukraine.

Trump, however, dismissed the spike and reiterated the White House's insistence that the rise was temporary.

"Short term oil prices, which will drop rapidly when the destruction of the Iran nuclear threat is over, is a very small price to pay for U.S.A., and World, Safety and Peace," he wrote on social media Sunday evening.

"ONLY FOOLS WOULD THINK DIFFERENTLY!" he argued.

Maritime traffic in the Strait of Hormuz – through which 20% of global crude and gas passes – has all but halted since Israel and the US launched the unprovoked war on February 28.

Oil and gas producers around the Gulf have meanwhile begun to decrease output, while Israeli strikes on fuel depots in Tehran have raised fears of retaliatory attacks on neighboring countries' infrastructure.

Soaring crude prices have already translated into rising costs at the fuel pump in the US, a highly sensitive political issue heading into midterm elections in November.

Earlier Sunday, Trump's energy chief Chris Wright also claimed that disruptions would be short lived.

Iran accounts for about 4% of world oil production, according to the US Energy Information Administration.

Its oil industry is subject to international sanctions but some is still exported, mainly to China, oil industry data shows.

US Treasury Secretary Scott Bessent said Friday that the government was considering lifting sanctions on more Russian oil, a day after it temporarily authorized India to buy from Moscow as global oil prices surged.