President Donald Trump has confirmed that Iran is in "serious discussions" with the United States amid a growing American military presence in the Gulf. He expressed hope that the talks would lead to something "acceptable," while tensions between the two nations remain high. Iran's top security official Ali Larijani also said there is progress on a negotiation framework. Trump has threatened intervention over Iran's nuclear program and the brutal crackdown on anti-government protests. Iran responded with a warning it would respond "immediately and powerfully" to any aggression on land or sea. Iran plans to start a two-day live-fire naval exercise on Sunday in the Strait of Hormuz, a key global shipping lane where about 20% of the world's oil passes. The strait is only 33 km wide at its narrowest point between Iran and Oman. Iran has previously threatened to close this route if attacked. The US has cautioned Iran against any "unsafe and unprofessional behaviour" near American forces. As part of its force buildup, the US sent the aircraft carrier USS Abraham Lincoln to the region, with Central Command confirming operations in the Arabian Sea. Iran's Foreign Minister Abbas Araghchi criticized the US military presence, saying it was trying to "dictate how our Powerful Armed Forces should conduct target practice in their own turf." Two explosions in Iran on Saturday raised fears. In Bandar Abbas, a blast killed one person and injured 14. Authorities blamed a gas leak, rejecting reports that a Revolutionary Guards commander had been targeted. Another explosion in Ahvaz killed at least four, also said to be caused by a gas leak. On Thursday, Trump said Iran must do two things to avoid US military action: "Number one, no nuclear. And number two, stop killing protesters." The Human Rights Activists News Agency reports over 6,300 killed since protests began in late December, investigating another 17,000 deaths. Iran Human Rights warns the toll may exceed 25,000. Protesters told the BBC that the security crackdown was more deadly than anything they had ever seen. Iran's Supreme Leader Ayatollah Ali Khamenei accused protesters on Sunday of attacking police, Revolutionary Guards, banks and mosques, stating, "The coup was suppressed," according to Tasnim news agency.