US President Donald Trump said negotiations with Iran would begin on Monday, after he called off planned military strikes on the country. Diplomatic efforts by Gulf nations, along with appeals from Tehran, persuaded him to delay the strikes, according to reports. Trump expressed hope for a negotiated settlement on Iran's nuclear programme and the Strait of Hormuz, saying an agreement with Iran was imminent. Mediators are working to revive an understanding regarding the waterway, and Tehran has urged Washington to honour a memorandum of understanding. However, Iranian officials rejected some accounts of formal agreements reached, and Tehran has not responded to the suggestion that new talks are imminent. The announcement sent oil prices down more than 4% on Monday as investors pared geopolitical risk premiums. Trump has previously said a negotiated end to the conflict was close, only for strikes to resume.