Asia stocks extend global rout as Iran war drags on

Asian stock markets were swept up in a global rout on Friday, tracking Wall Street lower as the threat of a protracted energy shock out of the war-torn Middle East sent borrowing costs spiralling higher.

Investors took a modicum of comfort from US President Donald Trump's decision to extend his ultimatum to strike Iranian power plants by 10 days, after pushing back his initial 48-hour deadline by five days. Brent crude futures fell 1.0 per cent to $US107.07 ($A154.62) a barrel having jumped nearly 6.0 per cent overnight.

However, movement in oil prices was small and reports that Trump was considering sending more troops only added to concern about the war escalating into a ground conflict, with no certainty that the Strait of Hormuz could be reopened to shipping soon.

Iran has dismissed a US proposal to end the conflict as "one sided and unfair".

Wall Street futures bounced 0.2 per cent in Asia. Overnight, the Nasdaq Composite slumped 2.4 per cent to be down nearly 11 per cent from its record close on October 29, confirming it has been in a correction since then.

"The Middle East headlines won't stop for the weekend so the weight of money leans towards assuming another risk-off week ahead as the US continues to add military resources to the region," said ITC Markets senior FX analyst Sean Callow.

"Many see the Iranian regime as holding the upper hand and doubt that there are indeed productive negotiations with the US in process... Underlying pressure towards higher oil prices, USD and yields along with weaker equities appears intact."

On Friday, MSCI's broadest index of Asia-Pacific shares outside Japan tumbled 1.4 per cent and was set for a weekly drop of 3.0 per cent. Japan's Nikkei skidded 1.3 per cent and was down 0.9 per cent for the week.

South Korea's KOSPI plunged 3.0 per cent, bringing its weekly loss to a staggering 8.5 per cent. Chinese blue chips fell 1.0 per cent, while Hong Kong's Hang Seng index slipped 0.4 per cent.

Citi analysts said more severe scenarios of the Middle East conflict could drag global growth below 2.0 per cent this year, push headline inflation beyond 4.0 per cent and stoke recession risk.

"Asia, particularly Korea, Japan, and India, faces the most intense headwinds due to heavy reliance on imported fuel and direct exposure to disruptions in the Strait of Hormuz," they said in a client note.

Norway's Norges Bank was the latest central bank to flag inflation risk and interest rate hikes ahead as the war rages on. Having held policy steady on Thursday, the bank said it expected to raise rates this year, a stark contrast with its earlier forecast of three cuts by the end of 2028.

Global bond yields jumped anew after the climb in oil prices amplified inflation concern. Japan's 10-year yields rose 4 basis points to 2.31 per cent, while Australia's benchmark 10-year yields surged 7 bps to 5.076 per cent.

The two-year US Treasury yield held steady at 3.9714 per cent on Friday, having jumped 10 basis points overnight as traders priced in more risk of a rate rise from the US Federal Reserve this year, which is about 50 per cent priced in.

In currencies, the US dollar was bathed in safe-haven glow having gained for three sessions. The risk-sensitive Australian dollar bore the brunt of market selloff, falling 0.2 per cent to a two-month low of $US0.6872 ($A0.9924) after a 0.8 per cent fall overnight.

The euro held at $US1.1533 ($A1.6655) after slipping 0.3 per cent overnight, while the yen hovered at 159.70 a dollar. Market watchers expect intervention should the yen hit 160.

Gold rose 0.6 per cent to $US4,405 ($A6,361) an ounce after a nearly 3.0 per cent fall overnight.