Iran said on Tuesday it would stop oil exports if pressure from Western sanctions got any tighter and it had a "Plan B” contingency strategy to survive without oil revenues.Western nations led by the United States have imposed tough sanctions on the Islamic Republic this year in an attempt to curb its nuclear programme that they say is designed to produce an atomic bomb. Tehran says its nuclear plans are peaceful."If sanctions intensify we will stop exporting oil,” Iranian oil minister Rostam Qasemi told reporters in Dubai.Qasemi’s statement is the latest in a series of threats of retaliation by Tehran in response to the sanctions, which have heightened political tensions across the Middle East and, analysts say, led to a sharp drop in Iranian oil exports."We have prepared a plan to run the country without any oil revenues,” Qasemi said, adding, "So far to date we haven’t had any serious problems, but if the sanctions were to be renewed we would go for ‘Plan B’."If you continue to add to the sanctions we (will) cut our oil exports to the world.”Iran has in the past said it could shut the vital shipping lane of Hormuz at the head of the Middle East Gulf, through which much of the region’s seaborne oil exports pass.Earlier on Tuesday, Qasemi said Iran was still producing 4 million barrels per day (bpd), rejecting reports the country’s output has fallen to around 2.7 million bpd.