ISTANBUL

The US dollar index climbed to 100.56 on Monday, its highest level since last May, as investors sought safety in the greenback amid escalating Middle East tensions and a sharp rise in oil prices.

The index, which measures the US currency against a basket of major peers, was last up about 0.16% after touching 100.56 earlier in the session as markets weighed the risk of a prolonged conflict and its inflationary fallout.

The dollar’s rise came as Brent crude traded above $116 a barrel and headed for a record monthly gain, fueling concerns that higher energy costs could complicate the outlook for inflation and monetary policy.

The US currency benefited from safe-haven demand and from the perception that the US economy is relatively more insulated from the oil shock because it is a net energy exporter.

At the same time, investors pared expectations for Federal Reserve rate cuts and increasingly considered the risk of a more hawkish policy response if energy-driven price pressures persist.

The euro fell 0.36% to $1.1466, while sterling dropped 0.54% to $1.3185, as concerns over growth and inflation weighed on European currencies.

In broader markets, investors remained focused on speeches from top Federal Reserve officials and the evolution of the conflict, with volatility across currencies, commodities, and equities expected to remain elevated.