Oil prices climb as US-Iran ceasefire expires

Oil prices crept higher and bond yields rose, blunting paltry gains for stocks at the start of Asian trading on Tuesday as a US-Iran truce expired and Tehran said it would shift to a "fully offensive" military posture.

MSCI's broadest index of Asia-Pacific shares outside Japan was up 0.8 per cent, buoyed by South Korea's KOSPI rising more than 3.0 per cent as the Seoul market returned after a holiday.

The Nikkei 225 fell 0.3 per cent, while S&P 500 e-mini futures were flat.

The yield on the US 10-year Treasury bond was up 0.8 basis point at 4.728 per cent. Its 30-year counterpart traded up 0.6 basis point at 5.3146 per cent, its highest in more than two decades.

"Typically, moves above 4.65 per cent for the US 10-year have been followed by some soothing words from the Trump administration, typically centred on an imminent resolution to the war with Iran," ING analysts wrote.

"This time, we're not hearing the same," they added. "In fact, the latest indications are for no imminent resolution as the shaky 60-day truce came to an end."

As the recent global selloff in bonds deepened, the yield on the 10-year Japanese government bond rose 2.5 basis points to 2.945 per cent, a three-decade high.

Overnight on Wall Street, the S&P 500 slipped 0.5 per cent while the Nasdaq Composite edged 0.3 per cent lower as soft US economic data, including an unexpected drop in retail sales, prompted markets to scale back bets on an imminent Federal Reserve interest rate move.

"Markets adopted a generally risk-off tone as President Trump reaffirmed he was not interested in extending the truce with Iran, with renewed tensions in the Middle East pushing oil prices higher and complicating sentiment," Westpac analysts wrote in a research note.

The US dollar index, which measures the greenback's strength against a basket of six currencies, traded around a two-month low of 99.527.

Oil prices rose more than $US2 ($A2.80) on Monday as the stalemate in Iran refocused oil traders on global supply worries. Brent crude futures edged up 0.2 per cent to $US91.06 ($A128.24) a barrel as trading resumed in Asia.

Gold was up 0.1 per cent at $US4,420.07 ($A6,224.57), extending recent gains into a third consecutive day.

In cryptocurrencies, bitcoin was up 0.1 per cent at $US64,398.48 ($A90,689.28), while ether gained 0.3 per cent to $US1,911.40 ($A2,691.73).