US President Donald Trump said he was unconcerned about the future of negotiations with Iran and dismissed worries over oil prices even if Tehran moves to block the strategically vital Strait of Hormuz, according to remarks made in a CNBC interview."I don't care if negotiations with Iran are over," Trump said, signalling a hardening stance amid escalating tensions in the Middle East and growing uncertainty around diplomatic efforts between Washington and Tehran.The comments come at a time when diplomatic efforts between Washington and Tehran appear to be unraveling. Iran has halted the exchange of messages with the United States through mediators, according to state-linked Tasnim news agency, signalling a tougher stance from Tehran as the conflict in the region enters its fourth month.Also Read: Iran suspends indirect US contacts, threatens wider pressure on key shipping routesTasnim reported that Iranian negotiators will not resume talks until their demands regarding Israeli military operations in Lebanon and Gaza are met. The agency also said Iran and the so-called "Resistance Front", comprising Tehran-backed groups in Lebanon, Iraq and Yemen, have agreed on a strategy to intensify pressure on Israel and its allies.Among the options being considered are efforts to shut the Strait of Hormuz and potentially widen pressure on other strategic maritime chokepoints, including the Bab el-Mandeb Strait. The developments have heightened concerns over global energy supplies and shipping routes.The Strait of Hormuz remains one of the world's most important energy corridors, handling a significant share of global crude oil and liquefied natural gas exports. The Bab el-Mandeb Strait, linking the Red Sea to the Gulf of Aden, is another critical trade artery and a gateway to the Suez Canal.Iranian Foreign Minister Abbas Araghchi on Monday accused the United States and Israel of violating the ceasefire, warning that "violation on one front is a violation of the ceasefire on all fronts" and that both countries would bear responsibility for the consequences.