NEW YORK, March 11 (Reuters) - Consumers will get relief from the rapid increases in fuel prices at the pumps in a month or two, John Catsimatidis, the billionaire owner of a Pennsylvania refinery and New York supermarket chains, told Reuters in an interview on Tuesday.

Supply disruptions caused by the Israel-U.S. war with Iran have sent fuel prices skyrocketing, posing a major threat to U.S. President Donald Trump and his Republican Party ahead of midterm elections in November.

"I believe prices will come back down in the next month, worst case scenario, two months," said Catsimatidis, a major Republican donor, who said he thought the worst of the increases was over.

The U.S. national average price of gasoline has gained nearly 60 cents since joint U.S.-Israeli attacks on Iran started February 28, and stood at $3.58 a gallon on Wednesday, AAA data showed. Diesel prices have risen more than $1, and Americans expect prices to rise over the next year, according to a Reuters/Ipsos poll that closed on Monday.

Three more ships were hit in the Strait of Hormuz on Wednesday as the war continues. The strait is a critical chokepoint for global oil supplies and its near-closure has forced Middle Eastern countries to cut crude oil production and their customers in Asia to reduce refining.

Catsimatidis, chairman and chief executive officer for United Refining Co, said the crisis highlights a need for more investment in U.S. oil production and refining, but it will require stability in White House policy. Asked if he would consider upgrading or expanding United Refining's 70,000 barrel-per-day refinery in Warren, Pennsylvania, he said: "Absolutely, yes."

The U.S. has not opened a major new refinery in nearly half a century, and energy experts questioned the need for one after Trump on Tuesday announced the construction of a plant on the southern U.S. border. U.S. refining economics are under pressure from the opening of mammoth new plants in Nigeria and elsewhere.