Chinese President Xi Jinping called Saudi Crown Prince Mohammed bin Salman on Monday to urge that the Strait of Hormuz (a narrow waterway linking the Persian Gulf to global shipping lanes, through which roughly a fifth of the world's oil passes) remain open to normal passage, as Beijing intensifies diplomatic efforts to contain the widening US-Iran conflict. Iran has largely restricted transit through the strait since the United States and Israel launched military operations in February, and a fragile ceasefire came under further strain after the US seized an Iranian cargo ship and Tehran signalled it would not join new peace talks. China, which is Iran's largest oil customer, called the US seizure a "forced interception" and urged all parties to honour the ceasefire, while Xi affirmed Beijing's support for Middle Eastern nations to determine their own futures and achieve long-term regional stability.