The Iranian government is taking an increasingly aggressive approach as it confronts a growing economic threat and worries that its grip on the Strait of Hormuz is slipping, analysts say.

By Tony Munroe and Alex Lawler SINGAPORE/LONDON, Sept 9 (Reuters) - Oil prices topped $100 a barrel on Wednesday for the first time in six weeks as an escalation in fighting by U.S. and Iranian forces deepened concerns over supply from the region and raised fears of inflationary pressures and higher energy costs for consumers and businesses.

Higher prices for gasoline and diesel fuel have soured Americans on the war and helped drive Trump’s approval rating into the toilet.

The weapons system officer was part of the two-man crew shot down over Iran, prompting one of the most complex rescue operations in U.S. military history.

Brent crude oil prices, a benchmark for global trading, climbed on Wednesday by about 2.7%, trading at about $100.57 a barrel for contracts with November dates. U.S. oil traded at about $95 a barrel, up by about 2%.

Donald Trump retained major oil and gas investments as the Iran war has moved energy markets. CNBC analyzed his holdings, trades and estimated gains.

Yemen's Tehran-backed Houthis attacked four cities in the south of U.S. ally Saudi Arabia on Tuesday, wounding more than 70 people and setting oil installations ablaze.

Saudi Arabia is vowing a resolute response to a wave of attacks from Yemen’s Iran-backed Houthi rebels early Tuesday that it said wounded at least 73 civilians.

Early in European trading, Brent crude, the global benchmark, reached $100, before slipping back below the significant milestone.