Most Asian shares were lower in morning trade on Monday, extending slides in global markets, as the impasse in the Middle East drove oil prices more than two percent higher.
Washington and Tehran agreed to a truce in April, but negotiations on ending the conflict have stalled and sporadic attacks in the region have continued, said AFP.
US President Donald Trump issued a fresh warning to Iran on Sunday, saying it had to move quickly towards a peace deal or "there won't be anything left of them".
The war has led to an effective blockade of the Strait of Hormuz, through which around 20 percent of global oil exports pass in peacetime.
The strait "remains meaningfully closed -- now approaching eleven weeks -- after the Trump-Xi summit in Beijing concluded without a breakthrough on reopening the waterway", MUFG's Michael Wan said Monday.
Tokyo shares lost 1.0 percent and Hong Kong was down 1.4 percent, while Shanghai was flat.
Sydney, Bangkok, Taipei, Singapore and Wellington also fell, with Jakarta tumbling 2.7 percent.
Seoul, which has renewed record highs in recent days thanks to the artificial intelligence stock boom, was trading up 1.2 percent.
"Global government yields rose sharply heading into the start of this week, as three forces collided: surging oil prices, fading hopes for a Strait of Hormuz resolution, and mounting fiscal concerns especially in the UK and US," Wan said.
However, last week's talks on trade between China and the United States have offered "a degree of relief for Asian markets", he added.
- 'Wave' of AI demand -
Data showed Monday that China's consumer spending in April grew at the slowest pace in more than three years -- a stark sign of the challenges Beijing faces to reignite domestic activity.
In Tokyo, shares in memory chip maker Kioxia were not yet trading after a reported rush of buy orders following stellar quarterly results on Friday.
Kioxia, the world's third-largest producer of NAND flash memory chips -- used as storage in AI data centres -- has seen its stock soar nearly 300 percent over the past year.
The firm has forecast an eye-watering 1.3 trillion yen ($8.2 billion) in operating profit for April-June, saying it is "riding the large wave of AI demand, which has led to record high revenue and profits".
In South Korea, Samsung Electronics -- which has also profited massively from the AI memory chip boom -- resumed union talks in a bid to avoid a strike over bonus payments, due to start Thursday.
Later Monday, traders will have their eye on a meeting of G7 finance ministers and central bank chiefs that kicks off in Paris, with bond selloffs in the spotlight, analysts said.
Then all eyes will be on quarterly results from US chip titan Nvidia, set for Wednesday, which will be scrutinized as tech investors question whether huge spending on AI data centers is justified by potential returns.
