The United States called on Iran to keep the straits of Hormuz and Bab al-Mandab open, a State Department official said on Tuesday a day after Washington demanded that Iran oil buyers halt their purchases by May 1. "We call on Iran, and all countries, to respect the free flow of energy and commerce, and freedom of navigation" in the straits, the official said. The Trump administration re-imposed sanctions on Iran, including on its energy sector, last November, after pulling America out of the landmark 2015 nuclear deal between Iran and world powers. The US has made a bad mistake by politicizing oil and using it as a weapon, Irans Oil Minister Bijan Zanganeh said in a parliamentary session on Tuesday. Zanganeh added that the United States will not be able to reduce Irans oil exports to zero. "With all our power, we will work toward breaking Americas sanctions," Zanganeh said in parliament. 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.