More uncertainty could be ahead following the recent U.S.-Israeli strikes against Iran over the weekend. The attacks have disrupted the flow of oil tankers traveling through the Strait of Hormuz, a critical sea passage and maritime choke point, the New York Times reported. As a result of shipping delays and suspensions, U.S. crude prices surged more than 12% on Monday, underscoring the economic risks of an escalating conflict in the Middle East.

When asked about the possibility of higher prices in March, Spence said “I wouldn’t be surprised.”

“Supply managers have yet another challenge on their hands,” she said. “This points to the need to really risk rate all your categories, understand where you’re getting supplies from, and whether it’s a pandemic or war or some other weather event or political event, we’re going to continue to encourage folks to play the worst case scenario in the planning and hopefully weather the storm.”

The “big six” categories, which also comprise petroleum and coal, as well as food, beverage and tobacco products, make up 72% of the sector’s gross domestic product.

S&P Global’s U.S. manufacturing PMI saw continued growth across the industry at 51.6%, but noted that it was the weakest in the past seven months. This was driven by softer rises in output and new orders as exports faltered.

“Businesses were often disrupted by extreme weather, which has clouded insights into the underlying strength of economic growth,” Chris Williamson, chief business economist at S&P Global Market Intelligence, said in a statement. “We may see some rebound once the weather clears,” noting improved optimism from manufacturers.

However, he added that uncertainty around tariffs could persist in the coming months as cost inflation remains elevated.