"For about a century, oil has constituted the basic and strategic components of US security foreign policy, the same role it played for the previous empires," Ahmadinejad said at the UN climate talks in Copenhagen.
"During this period, oil-rich regions of the world became the theatres of wars and military adventurism that led to foreign domination on their energy resources."
The United States, he said, gobbled up a quarter of the world's oil and energy supplies yet had only five per cent of the world's population.
"Almost 40 percent of the total motor vehicles of the world are moving in this country by occupying and controlling oil wells in other countries," according to a translation of Ahmadinejad's speech.
"The country's military budget is almost equivalent to the military budgets of the majority of countries altogether, and it has an active presence in all armed conflicts and wars in the world."
The attack was centrepiece of an argument whereby Ahmadinejad declared that climate change was caused by capitalism and the rush to exploit cheap and plentiful fossil fuels.
Among solutions, he said "all countries" should be able to gain access to nuclear power to help ease the greenhouse-gas emissions that stoke global warming.
Tehran is at loggerheads with Western countries, which suspects its nuclear programme — which Iran says is of purely civilian intent — aims at creating an atomic bomb.
"All countries must gain access to new technologies to diversify their energy sources and be able to use clean and renewable energy such as wind, solar, sea tide, geothermal and nuclear energies," he said.
The United States and its regional ally Israel have not ruled out a military option to stop Tehran's controversial nuclear drive.
Tehran has in the past threatened to target US bases in the region and to block the strategic Gulf Strait of Hormuz waterway for oil tankers if its nuclear sites are attacked.
Iran is under three sets of UN sanctions for refusing to suspend enrichment and risks a further round after rejecting a UN-brokered deal to send its low enriched uranium abroad to be further refined into fuel for a research reactor.
The major powers negotiating with Iran on its nuclear program are to discuss the situation next week by telephone, probably on Tuesday, a US diplomat, speaking on condition of anonymity, said on Wednesday.
Iran on Wednesday unleashed international condemnation after it test-fired what it said was a faster version of a medium-range missile, Sejil 2 (Lethal Stone).
The weapon had a potential range of 2,000 kilometres (1,240 miles), placing arch-foe Israel, most Arab states and parts of Europe within range.
