President Donald Trump (79) defended his military campaign against Iran in his first nationwide address more than a month into the conflict, claiming the United States was nearing victory despite sinking approval ratings and rising oil prices.

In a 19-minute televised speech from the White House’s Cross Hall on Wednesday evening, Trump said the war would continue for two to three weeks more of “extremely hard” strikes against Iran.

“We are going to finish the job, and we’re going to finish it very fast. We’re getting very close,” he said.

The president outlined the United States’ objectives as crushing Iran’s military, ending the clerical state’s support for regional armed groups and preventing it from obtaining a nuclear bomb. The UN nuclear watchdog and many observers have said such a prospect was not imminent.

“I’m pleased to say that these core strategic objectives are nearing completion,” Trump said. “In these past four weeks, our armed forces have delivered swift, decisive, overwhelming victories on the battlefield.”

Israel killed Iran’s longtime supreme leader, Ayatollah Ali Khamenei, on the first day of the conflict launched on February 28. Trump said “their leaders, most of them” in Iran are dead.

However, Iran has taken control over the Strait of Hormuz, the passageway into the Gulf for one-fifth of the world’s oil, which was open before the war.

Petrol prices in the United States have surged above $4 a gallon for the first time in years, whilst consumer confidence has weakened.

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Recent polling shows Trump’s overall approval rating slipping below 40%, with disapproval climbing above the mid-50%. The war itself is deeply unpopular with segments of his own Republican Party.

Trump again threatened that if Iran does not reach a negotiated settlement, the United States would “hit each and every one of their electric generating plants”. Attacks on civilian energy infrastructure are widely considered illegal under the laws of war and could constitute a war crime.

“Over the next two to three weeks, we are going to bring them back to the Stone Ages, where they belong,” Trump said.

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Earlier on Wednesday, Trump claimed Iranian President Masoud Pezeshkian was seeking a ceasefire. This was swiftly denied by Iran’s foreign ministry, which also accused Washington of making “maximalist and irrational” demands.

“We have all the cards. They have none,” Trump said.

He offered conciliatory words to Gulf Arab allies that have been hit by Iranian retaliatory fire, saying he would not let them “get hurt or fail”.

However, he criticised European allies that have declined to support the war, on which he did not consult them in advance. The countries that “receive oil through the Hormuz Strait must take care of that passage,” Trump said, urging them to “build up some delayed courage”.

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