Chevron CEO Mike Wirth is predicting the world's oil supply will soon begin experiencing physical shortages across the globe, which will begin having noticeable impacts on national economies. 

Exports through the Strait of Hormuz, a vital waterway through which 20% of the world's crude oil is moved, remained effectively closed this week as a result of the war in Iran. 

During the discussion sponsored by the Milken Institute, Wirth said economies will begin shrinking, starting with Asia and then Europe would follow, as demand responds to rising prices. He said the surplus supply in commercial markets, tankers in fleets skirting sanctions and national strategic reserves were being used up, Reuters reported. 

"Economies are going to have to slow," Wirth said. 

The U.S., as a net exporter of crude oil, wouldn't see nearly the impacts other parts of the globe will experience, but it won't be entirely shielded, Wirth said. 

California, which depends on imports of crude oil due to its climate policies, is particularly vulnerable. In the discussion, Wirth pointed out that the last shipment of oil from the Gulf was being offloaded in the Port of Long Beach.