Brent fell below $90 a barrel for the first time since August after US President Donald Trump said further US military action against Iran was no longer necessary and that the war could end soon. Brent, the benchmark for two thirds of the world's oil, slid briefly below $90 per barrel to inch upwards to $90.32 a barrel at 1.33pm UAE time. West Texas Intermediate, the gauge that tracks US crude, was trading 2.27 per cent lower at $84.77a barrel.