Oil prices tumble as US halts Iran airstrikes; Brent falls below $90

International oil prices tumbled on Monday (local time) after the United States halted airstrikes against Iran over the weekend. Brent crude for September delivery closed at $88.36 a barrel on the ICE Futures Exchange, down 8.7 percent from the previous session.

West Texas Intermediate crude for September delivery settled at $82.61 a barrel on the New York Mercantile Exchange, down 7.5 percent. It was the first time Brent futures had closed below $90 a barrel since July 20.

Brent futures had surpassed $100 a barrel last week as tensions spread from the blockade of the Strait of Hormuz to the Red Sea, which had been used as an alternative shipping route.

Over the weekend, the US suspended its two-week campaign of airstrikes against Iran, and Iran refrained from retaliatory attacks, bringing the armed conflict to a temporary lull.

According to CNN, President Donald Trump ordered a halt to the airstrikes on July 24. US Ambassador to the UN Mike Waltz, appearing on NBC on Monday, said, "What the president is doing right now is, as we've seen, leaving some room for dialogue."

Some US media outlets have suggested that the US was in effect forced to suspend the strikes as its stockpile of interceptor missiles was rapidly depleted.

However, energy industry experts cautioned that crude shipment volumes remain severely constrained, and that oil prices could swing sharply depending on how the armed conflict between the US and Iran develops.

Alex Hodes, an energy strategist at futures brokerage StoneX, said maritime cargo volumes "remain severely depressed even after the brief truce in mid-June," adding that "Saudi Arabia's Red Sea cargo has no choice but to use the longer, more costly rerouting through the Suez Canal."