By Rae Wee

SINGAPORE (Reuters) -Asian shares slumped and gold prices rose on Monday as risk sentiment took a hit after Iran's retaliatory attack on Israel stoked fears of a wider regional conflict and kept traders on edge.

The dollar scaled a fresh 34-year high against the yen on growing expectations that sticky inflationary pressures in the United States will keep rates there higher for longer.

Markets in Asia began the week on a cautious footing. MSCI's broadest index of Asia-Pacific shares outside Japan fell 0.7% after Iran had, late on Saturday, launched explosive drones and missiles at Israel in retaliation for a suspected Israeli attack on its consulate in Syria on April 1.

That marked Iran's first direct attack on Israeli territory.

The threat of open warfare erupting between the arch Middle East foes and dragging in the United States has left the region on tenterhooks. U.S. President Joe Biden warned Prime Minister Benjamin Netanyahu the U.S. will not take part in a counter-offensive against Iran.

Israel said "the campaign is not over yet".

Japan's Nikkei slid more than 1%, while Australia's S&P/ASX 200 index lost 0.6%.

Hong Kong's Hang Seng Index slumped 0.8%.

The escalating tensions also sparked a flight to safety that sent gold rising 0.51% to $2,356.39 an ounce and the safe-haven dollar broadly higher, extending its 1.6% rise from last week. [GOL/]

Oil prices, however, hardly reacted to the news, as traders had largely priced in a retaliatory attack from Iran that would likely further disrupt supply chains. That saw Brent crude futures peaking at $92.18 a barrel last week, the highest level since October.

Brent was last 0.5% lower at $90.01 per barrel, while U.S. West Texas Intermediate crude futures fell roughly 0.6% to $85.13 a barrel. [O/R]

"The key risks for the global economy are whether this now escalates into a broader regional conflict, and what the response is in energy markets," said Neil Shearing, group chief economist at Capital Economics.

"A rise in oil prices would complicate efforts to bring inflation back to target in advanced economies, but will only have a material impact on central bank decisions if higher energy prices bleed into core inflation."

U.S. stock futures, meanwhile, ticked higher, after a heavy selloff on Wall Street on Friday as results from major U.S. banks failed to impress. [.N]

S&P 500 futures and Nasdaq futures each rose 0.15%.

"Geopolitical headlines are going to be very much there," said Chris Weston, head of research at Pepperstone.

"The market is really trying to understand what's going on. Their visibility to price risk in this market has become a bit more troublesome, and I think when you don't have that visibility, you do get higher volatility. That's kind of where we are."

RATE RETHINK

Elsewhere, U.S. Treasury yields held near their recent highs as traders pared back their expectations of the pace and scale of rate cuts from the Federal Reserve this year. [US/]

The benchmark 10-year yield last stood at 4.5277%, while the two-year yield held near the 5% level and was last at 4.8966%.

A continued run of resilient U.S. economic data, particularly last week's hotter-than-expected inflation report, has added to the view that U.S. rates could remain higher for longer, and that a Fed easing cycle is unlikely to commence in June.

Futures now point to about 50 basis points worth of easing expected this year, a huge pullback from the 160 bps that was priced in at the start of the year.

That sea change in the rate outlook has in turn sent the dollar on a tear, pushing it to a 34-year peak of 153.69 yen on Monday.

The euro and sterling were similarly pinned near five-month lows. [FRX/]

"We have updated our forecasts for the U.S. FOMC, pushing out the timing of the start of the interest rate cutting cycle to September 2024, from July previously," said Kristina Clifton, a senior economist at Commonwealth Bank of Australia (OTC:CMWAY).

"The U.S. CPI has been stronger than expected over the first three months of 2024. We expect that it will take a string of inflation prints of 0.2%/month or lower to give the Fed confidence that inflation can stay sustainably lower and that interest rates do not need to remain at a restrictive level."

A slew of Fed policymakers are due to speak this week, including Chair Jerome Powell, who could give further clarity on the future path of U.S. interest rates.

The shift in rate expectations has halted bitcoin's blistering rally, after the world's largest cryptocurrency repeatedly notched fresh records this year thanks to flows into new spot bitcoin exchange-traded funds and expectations of imminent Fed cuts.

Bitcoin was last more than 2% lower at $65,536, after falling below $62,000 on Sunday. [FTX]