Other key factors then emerged: the ongoing Russia-Ukraine conflict that started in February and the subsequent banning of Russian energy imports by the US.

However, for a second straight week, average gasoline prices in the US fell. As of April 4, they dropped by 5.4 cents from the week before to stand at $4.17 per gallon (3.78 liters), according to the price-tracking website GasBuddy, which compiled more than 11 million reports covering over 150,000 gas stations across the country.

The national average price was up by 25.5 cents from a month ago and $1.31 per gallon higher than a year ago. Meanwhile, in the week to April 4, the national average price of diesel fell by 3.6 cents to $5.08 per gallon.

Patrick De Haan, head of petroleum analysis at GasBuddy, wrote on April 4, "So long as oil prices remain under $100 per barrel and there are no escalations in Russia's war on Ukraine, we may be poised to see gas prices decline again this week as the US and other countries try to raise oil supply to tip prices lower."

De Haan told China Daily, "The SPR release may not bring direct relief but may offer a ceiling for how high oil prices go, depending on how circumstances play out, especially the possibility that the EU could (increase) sanctions on Russia's oil and gas."

Referring to tapping the SPR, he said: "It does appear that this may be politically induced, trying to offer motorists relief from the record prices. Some of the rise can be blamed on the optics surrounding the US' desire to move away from fossil fuels, yes, though it's had an indirect and thus far limited impact.

"Most of those decisions change the 'optics' of oil and gas and will have greater effect in the years to come."

Chemical engineer Robert Rapier wrote on the Oilprice website: "Whether that decline (in prices) can be sustained is really dependent upon just how quickly US oil production continues to ramp up－as well as what happens with Russian oil supplies. It's highly unlikely that US production will increase by 1 million BPD (barrels per day) in the next six months, but that timing will also mark the end of the high-demand (summer travel) season in the US.

"So it's possible that the impact will be sustained. Furthermore, six months from now is just before the November elections, so additional releases could be announced if the current releases don't have the desired impact."

Yifan Xu in Washington contributed to this story.