Iran threatened again on Sunday to close the Strait of Hormuz with its chief of staff saying the Revolutionary Guards Corps (IRGC) had not observed any change in the US military’s behavior towards the force after the blacklisting. “US warships are obliged to respond to the IRGC on the passage of the Strait of Hormuz ... and until yesterday they have been answering IRGC questions, and we have not seen change in their procedures,” Major General Mohammad Baqeri was quoted as saying on Sunday by the semi-official Fars news agency. Earlier this month, the United States blacklisted IRGC and demanded buyers of Iranian oil stop purchases by May or face sanctions. Lieutenant Chloe Morgan, US Naval Forces Central Command spokeswoman, said on Sunday: “The Strait of Hormuz is an international waterway. Threats to close the strait impact the international community and undermine the free flow of commerce. “The US, along with our allies and partners, is committed to freedom of navigation and remains well positioned and postured to preserve the free flow of commerce, and we are prepared to respond to any acts of aggression,” Morgan said in an emailed statement, without referring to interaction with IRGC forces. “We don’t intend to close the Strait of Hormuz, unless hostilities reach a level where this cannot be avoided,” Fars quoted Baqeri as saying. “If our oil does not pass, the oil of others shall not pass the Strait of Hormuz either.” President Hassan Rouhani and some senior military commanders have threatened to disrupt oil shipments from Gulf countries if Washington tries to strangle Tehran’s oil exports. Tensions between Tehran and Washington have risen since the Trump administration withdrew last year from a 2015 international nuclear deal with Iran and began ratcheting up sanctions.