Brent oil prices opened the week more than 1.5% higher, rising to almost $82 per barrel as investors grew again skeptical about the ability of the US and Iran to sign a lasting peace deal in the Middle East. Although the two countries resumed talks in Switzerland, last week's memorandum of understanding appears to have broken down. Iran said the US had failed to secure a ceasefire in Lebanon and announced it had again halted traffic through the strait. Tehran also said Sunday's talks would exclude substantive issues such as its nuclear programme. Meanwhile, President Trump warned of renewed US strikes unless Iran curbs its proxies in Lebanon. He also threatened tolls in the absence of a deal and warned Tehran against closing the Strait of Hormuz.