Oil prices are rising in early trading as a standoff between Iran and the U.S. prevented tankers from using the Strait of Hormuz. The price of U.S. crude oil increased 6.4% to $87.90 per barrel an hour after trading resumed on the Chicago Mercantile Exchange. The price of Brent crude, the international standard, climbed 5.8% to $95.64 per barrel. The market reaction followed more than two days of lifted hopes and dashed expectations involving the strait. Crude prices plunged more than 9% on Friday after Iran said it would fully reopen the strait to commercial traffic. The country's government reversed course on Saturday after the U.S. vowed to maintain a naval blockade of Iranian ports.