Global crude oil prices have risen once again, driven by uncertainty surrounding peace talks aimed at ending the conflict involving Iran. On Sunday, the price of Brent crude climbed 3.17 percent, reaching $104.50 per barrel. Meanwhile, the price of U.S. crude oil rose 3.21 percent to approximately $98.48.

It appears that peace negotiations between the United States and Iran have once again stalled. Consequently, fresh concerns have emerged regarding when oil shipments through the Strait of Hormuz—a vital Middle Eastern maritime route—will return to normal.

Mike Waltz, the U.S. Ambassador to the United Nations, told Fox News Sunday that the United States has established a “very clear red line”—or final boundary—in its latest proposal. Although Iran responded to this U.S. proposal, President Donald Trump dismissed it as “completely unacceptable.”

Due to the absence of a peace agreement in recent weeks, the prospects of reopening the Strait of Hormuz—a critical maritime route through which nearly one-fifth of the world’s total oil and gas is transported—are being hindered.

According to reports from Iran’s state-run media, a senior military official from the country issued a warning: vessels belonging to nations currently enforcing sanctions against Iran will “face difficulties” when attempting to traverse the strait.

Meanwhile, the United States has maintained its naval blockade against Iranian vessels and ports. Last Friday, U.S. forces attacked two Iranian-flagged oil tankers that attempted to defy the blockade.

Currently, the price of crude oil stands at approximately $20 per barrel higher than it was prior to the outbreak of the conflict, while the price of U.S. crude is up by about $10. Americans are having to pay more as a result of these elevated oil prices.

According to data from the American Automobile Association (AAA), the average price of gasoline in the country is now $4.52 per gallon. Prior to the start of the conflict, this figure was below $3.