Iran’s Islamic Revolutionary Guard Corps (IRGC) has announced that it is closing the Strait of Hormuz—one of the world’s most critical sea routes—until further notice. The move has pushed tensions higher as the United States said it has begun a new phase of strikes against Iran.

Although a recent peace agreement was signed between Iran and the US, both sides have continued to carry out attacks. US President Donald Trump said there was no benefit in further talks with Iran and declared the ceasefire over, while also stating that negotiations would continue.

For the past three days, the two countries have exchanged strikes. The US has carried out missile attacks on Iran, while Iran has retaliated by targeting American military bases in West Asian countries.

Amid the escalation, Iran and Oman reportedly held talks on the Strait of Hormuz, discussing the future of maritime movement and agreeing to continue discussions. Iran’s Foreign Minister Abbas Araghchi said the meeting explored “appropriate ways” to ensure the safe passage of ships.

Soon after the IRGC’s closure announcement, the US Central Command said American forces started attacks on Iran within minutes. Separately, Trump said 1,000 missiles were aimed at Iran, and Iran’s new supreme leader Mojtaba Khamenei issued a statement vowing revenge for the killing of his father, further intensifying the crisis.