American motorists could soon pay more at the pump amid spiking oil prices due to the U.S.-Israel attacks on Iran, with experts predicting gasoline prices could rise sharply this week.

European defence stocks rose at the start of the week as investors anticipated that the widening conflict in the Middle East will push up demand for munitions and military hardware.

Attacks throughout the region, including on two vessels traveling through the Strait of Hormuz, the narrow mouth of the Persian Gulf, could restrict countries' ability to export oil to the rest of the...