NEW YORK — Renewed tensions between Iran and the West pushed oil to its highest level in more than a month.

Iran is again threatening to block a critical Persian Gulf shipping route in response to a European embargo of Iranian oil. Iran has sparred for months with the West over its nuclear program.

Benchmark U.S. crude added $3.91, or 4.7 percent, to end at $87.66 per barrel in New York, the highest price since May 30.

Brent crude, which sets the price of oil imported into the United States, rose above $100 for the first time in three weeks. Brent added $3.34, or 3.4 percent, to finish at $100.68 per barrel in London.

Combined with a big gain Friday, oil has risen by nearly $10 per barrel in less than a week. That’s bringing an end to a prolonged drop in pump prices. The national average price for gas rose slightly Tuesday to $3.30 per gallon, the first increase in more than two months.

An increase in U.S. factory orders from April to May also supported oil prices Tuesday. And analysts are betting that Europe, China and the U.S. will take steps to stimulate their economies, which would boost oil demand.

But the main driver was Iran. More than a third of the world’s seaborne oil is shipped out of the Persian Gulf, so any move by Iran to shut the vital Strait of Hormuz raises the risk of a confrontation and the disruption of tanker traffic. Iran has threatened to block the waterway since late last year when Western nations imposed financial sanctions and the European Union first proposed an oil embargo.

The dispute is over Iran’s nuclear program. The West says Iran is enriching uranium to eventually build nuclear weapons. Iran denies the claim.