ADEN/DUBAI — Middle East diplomacy appeared to falter heading into Monday with the postponement of a meeting between Iran and other Persian Gulf powers, while fresh attacks around the region’s two most important oil transit routes deepened concern over global energy supplies.

Oil prices jumped as markets reopened on Monday, following developments that threaten supplies from the world’s biggest exporter, Saudi Arabia, which kept a key 1,200-km (745-mile) east-west pipeline closed throughout the weekend after it was damaged in drone strikes on Friday.

Iran’s foreign ministry had said there would be a meeting hosted by Oman where the future of the Strait of Hormuz, vital for global oil and gas flows, would be negotiated.

Tehran said Iraq and Gulf countries would take part, without specifying which states, but no country in the region had confirmed its participation while Bahrain ruled out attending.

“It has been decided to postpone to a later date the regional meeting that was to be held on Monday in Salalah, in order to create conditions conducive to a constructive dialogue,” the Oman News Agency said on Sunday.