Japan's Nikkei share average ended Monday's session higher, helped by a fall in oil prices after a halt in U.S. attacks on Iran, while investors stayed cautious before major earnings due this week.

The benchmark Nikkei rose 0.5% to close at 64,931.19 after fluctuating between gains and losses. The broader Topix rose 1.37% to 4,066.07.

The U.S. suspended its bombing campaign on Iran after nearly two weeks of heavy airstrikes, while a senior Iranian official told Reuters Tehran would also halt its own attacks as long as Washington did the same. Oil prices fell more than 6% on Monday on expectations of a diplomatic off-ramp.

"Reduced concern over higher crude prices should support Japanese shares overall, while buybacks are also expected in stocks that had seen an increasingly corrective tone through last week," said Takayuki Miyajima, senior economist at Sony Financial Group.

"However, with major U.S. cloud companies due to report earnings this week, investors may be reluctant to aggressively chase the upside as they assess capital spending plans and the monetisation of AI investment," he said.

Investors are focused on a busy week of earnings announcements in the U.S. and Japan, as well as central bank decisions.

In Tokyo, chip-testing equipment maker Advantest is due to report earnings on Wednesday, while memory chipmaker Kioxia is scheduled to report on Friday.

Market breadth was positive, with 194 advancers on the Nikkei 225 against 31 decliners.

Software testing and quality assurance services provider Shift was the top percentage gainer on the index, rising 9.32%, followed by consulting services provider BayCurrent, up 8.95%, and Shiseido, a global cosmetics and skincare company, which rose 7.62%.

Shares of Shin-Etsu Chemical slid 8.3%, making the silicon and chemical products maker the Nikkei's biggest percentage loser, after its full-year consolidated net profit outlook undershot market expectations. It was the stock's steepest percentage loss since January.

Optical fibre producer Fujikura lost 5.83% and SoftBank Group, a tech investment conglomerate, shed 3.07%.