Oil prices were near 2019 highs on Tuesday after Washington announced all Iran sanction waivers would end by May, pressuring importers to stop buying from Tehran. Brent crude futures were at $74.40 per barrel at 0239 GMT, up 0.5 percent from their last close and not far off a 2019 peak of $74.52 reached on Monday. US West Texas Intermediate (WTI) crude futures hit their highest level since October 2018 at $65.95 per barrel before edging back to $65.89 by 0239 GMT, which was still up 0.5 percent from their last settlement. The United States on Monday demanded that buyers of Iranian oil stop purchases by May 1 or face sanctions, ending six months of waivers which allowed Iran’s eight biggest buyers, most of them in Asia, to continue importing limited volumes. Before the reimposition of sanctions last year, Iran was the fourth-largest producer among the Organization of the Petroleum Exporting Countries (OPEC) at almost 3 million barrels per day (bpd), but April exports have shrunk well below 1 million bpd, according to ship tracking and analyst data in Refinitiv. Barclay’s bank said in a note following the announcement that the decision took many market participants by surprise and that the move would “lead to a significant tightening of oil markets.” The British bank added that Washington’s target to cut Iran oil exports to zero posed a “material upside risk to our current $70 per barrel average price forecast for Brent this year, compared with the year-to-date average of $65 per barrel.”