SINGAPORE/LONDON - Oil and the dollar jumped on Monday as the failure ‌of US-Iran talks to yield an agreement left a fragile ceasefire hanging in the balance and no end to a choke on Middle East energy exports.

S&P 500 futures dropped 1 percent in early trade. Benchmark Brent crude futures surged 8 percent to $103 a barrel. The euro fell ​about 0.5 percent to $1.1672.

Moves in Asian stock markets were broadly lower but relatively modest, with investors reluctant to ​make big bets as they waited for signs of some form of a negotiated end ⁠to a six-week conflict that has already pushed oil prices more than 30 percent higher.

Japan's Nikkei fell 0.4 percent, South Korea's ​KOSPI slumped 1.4 percent and the S&P/ASX 200 slipped 0.6 percent.

Marathon talks in Islamabad ended in stalemate and with the US ​announcing a blockade of the narrow Strait of Hormuz, the choke point of the Persian Gulf.

The Wall Street Journal reported Trump and his advisers were weighing limited strikes on Iran, though ​there were no immediate reports of attacks in early Asian trading to shatter a fragile US-Iran ceasefire that has ​largely held since last week.

"The market is now largely back to conditions before the ceasefire, except now the US will block ‌the remaining ⁠up to (2 million barrels) Iranian-linked flows through the Strait of Hormuz as well," said MST Marquee analyst Saul Kavonic.

"The key remaining question is if the US renews strikes on Iran, raising the risk of strikes on energy infrastructure across the region which could have a further lasting impact beyond the duration of the war."

US Treasury futures sank in early ​trade and gold, which has ​been a loser as ⁠investors have cashed out profits from its long pre-war rally, fell almost 2 percent.

Risk-sensitive currencies such as the Australian dollar and sterling came under pressure, falling 0.7 percent and 0.5 percent, respectively. ​The dollar rose 0.3 percent to 159.78 yen.

With inflation fears reviving, investors are now bracing for central banks, such as the European Central Bank and Bank of England, tilting towards raising rates in a sharp ⁠reversal ​from pre-war bets on rate cuts or a prolonged pause.

Trump said on ​Sunday that the price of oil and gasoline may remain high through November's midterm elections, a rare acknowledgement of the potential political fallout from ​the war.