Iran vowed on Tuesday that not one litre of oil would be exported from the Gulf while its war with the United States and Israel continues, in a stark rebuke to President Donald Trump's boast that the conflict was all but over.Trump's argument that the war would be "ended soon" helped reverse the previous day's spike in oil prices, which have surged since Iranian attacks on shipping closed the strategic Strait of Hormuz in response to the US-Israeli strikes that killed its supreme leader.