Japanese shares rose at the start of trading Monday on growing optimism that an agreement to reopen the Strait of Hormuz and resume oil shipments is closing in.
The Nikkei 225 climbed 319.9 points or 0.5% to open at 63,658.95.
Senior U.S. officials said Sunday that Washington and Tehran are nearing a deal, though talks on key language continue and final approval may take several more days, according to media reports.
However, Iran's Tasnim news agency cautioned that the draft accord might still fall apart, accusing the U.S. of blocking key provisions, such as Tehran's demand for the unfreezing of its assets, the reports said.