Iran has described the United States response to its seven conditions for reopening the Strait of Hormuz as unconvincing, even as President Donald Trump confirmed that American forces carried out strikes on an Iranian island near the strategic waterway.

The developments on Tuesday unfolded while Qatar intensified diplomatic efforts to head off a renewed war between Washington and Tehran, and as another oil tanker came under attack in the strait.

The indirect negotiations revolve around an Iranian proposal to reopen the waterway over two days, provided the US meets Tehran's seven demands, which include lifting sanctions and ending the American naval blockade. Despite reports of progress in recent days, Mohsen Rezaei, secretary of Iran's Supreme National Security Council, said on Tuesday that Washington's reply had fallen short.

"America's response to Iran's rights and demands was not convincing, and they must fully and explicitly address Iran's seven conditions and act upon them," Rezaei wrote on X. "Only in this case will the Strait of Hormuz be reopened."

His statement followed remarks from Majed al-Ansari, a spokesperson for Qatar's Ministry of Foreign Affairs, who said talks were continuing and that both sides "remain committed to the negotiation process." He said Qatar was facilitating the "real-time exchange of proposals between" the US and Iran.

In Washington, Trump told Fox News that US forces had struck Iran early on Tuesday, targeting an anti-aircraft facility. He called the operation a "minor attack" and insisted it "wasn't war." "They built an anti-aircraft facility. It took them about two months. We watched it get built. As soon as it was completed, we hit it last night," he said. Iranian media reported the strikes hit Qeshm Island in the Gulf, near the Strait of Hormuz. Earlier, US officials told American media the strikes were defensive and came after Iranian fire at an American aircraft.

US media, citing officials, also reported that Central Command has drawn up plans for strikes that could begin as early as Wednesday, after the midterm elections, when three American aircraft carriers will be in the region. The pivotal vote could cost Trump's Republicans control of both the House and the Senate, and fears have grown that he could order a threatened attack on Iran once polling ends. Previous US media reports described the planned campaign as short and intense. Trump repeated warnings of further action on Tuesday, saying, "I'm not looking to .. kill lots of people" and "If we have to, we'll have to." In an earlier interview with the Financial Times, he suggested he was satisfied with the state of the stand-off, telling the paper in a six-minute telephone call: "We seem to be getting everything we want."

Iran's supreme leader, Mojtaba Khamenei, ordered the military at the weekend to answer any threat immediately and without geographical limits, and to update its list of targets. Iranian officials have suggested that European countries and undersea cables in the Gulf could be hit.

Commercial shipping also faced further danger. The United Kingdom Maritime Trade Operations reported that two unidentified projectiles struck a tanker's engine room about 14 nautical miles (26km) northeast of Oman's coastal village of Limah on Tuesday, with no casualties reported. Separately, the Islamic Revolutionary Guard Corps claimed four tankers had struck mines and caught fire after switching off navigation and identification systems and using what it called unauthorised routes through Hormuz, and said its forces had seized two other vessels. That account could not be independently verified or linked to the incident reported by UKMTO. The IRGC also claimed it destroyed two US LUCAS attack drones over Bandar Khamir, according to Iranian state broadcaster Pars Today.

John Mearsheimer, a US political scientist, questioned whether another short bombing campaign could achieve Washington's goals, warning that Iranian retaliation could pull the US into a longer confrontation. "If the 40-day bombing campaign didn't work, how is the three-day bombing campaign going to work?" he asked in a video commentary, referring to the initial US-Israeli air campaign and proposals for a shorter renewed offensive. He argued that an Iranian response could trigger further US escalation, deepening the damage to the global economy.