TOKYO -- Global bond yields are facing persistent upward pressure despite falling oil prices, as uncertainty over the conflict in the Middle East keeps investors guessing and fiscal fears resurface.

Overnight on Wall Street, the yield on the 30-year U.S. Treasury hit 5.62%, its highest level in roughly 24 years. The benchmark 10-year yield also remained elevated, at 5.23%. The selloff spilled into Tokyo on Wednesday morning, with the yield on the benchmark 10-year Japanese government bond rising to 3.095%. The 20-year and 30-year yields also climbed. Bond yields move inversely to prices.

European bond markets saw similar moves. On Tuesday, yields in Germany and the U.K. briefly climbed to multidecade highs.

According to a report by BMI, a unit of Fitch Solutions, the rise in interest rates has extended across the U.S. yield curve, particularly in the "belly," or intermediate maturities, with similar shifts seen in other economies.

"The whole curve for the U.S. has shifted higher, particularly at the 'belly,' a trend we have seen for other economies as well," the report said. Higher yields reflect "a combination of stronger growth, higher inflation, growing fiscal concerns as well as significant issuance by hyperscalers," the report said, referring to large tech companies that operate massive cloud computing and data center networks. Yields stayed hot despite a drop in oil prices.

Oil futures have fallen from their recent peaks, with West Texas Intermediate (WTI) crude trading around $90 per barrel on Wednesday, down from over $100 earlier this month. Brent futures have also stabilized from their September peak of around $110 per barrel to $103 now.

The recent decline comes as fears of a supply crunch subside. Earlier this month, worries grew after military strikes in the Middle East damaged tankers and Saudi energy facilities. However, oil prices remain higher than they were before the Middle East conflict broke out in late February, when WTI and Brent were trading around $60 to $70 a barrel.

Uncertainty over the U.S.-Iran conflict remains high. U.S. President Donald Trump on Saturday revealed that he rejected a conditional Iranian proposal to reopen the Strait of Hormuz. On Sunday, he said Washington is "very seriously" considering a ban on U.S. diesel exports to hold down domestic prices amid political pressure over high fuel costs ahead of the November midterm elections. U.K. diesel prices have surged to a record high, according to motoring body RAC on Monday.

"The diesel export ban discussion is the most consequential near-term policy question for energy markets," Rystad Energy chief economist Claudio Galimberti said in a note. A formal ban would push prices "sharply higher in Europe and Latin America," he said, explaining that product stocks are already low. In the U.S., gasoline and jet fuel prices "would rise over time as U.S. Gulf Coast refiners would be forced to reduce their runs before long," he added.

As for the prospects of a resolution with Iran in October, Galimberti said such an outcome was unlikely.

Alongside concerns over sticky inflation, fiscal worries are also weighing on bond markets. Trump has promised to give $5,000 to every adult American if his Republican Party wins the midterm elections. In France, where efforts to repair public finances have lagged, a presidential election will be held next year, fueling concerns over the possibility of more expansionary policies.

Public-sector net borrowing in the U.K. reached 18.3 billion pounds ($23.8 billion) in August, according to data released by the Office for National Statistics last week, far exceeding forecasts.

Markets are struggling to gauge the pace of rate hikes by central banks. According to the CME FedWatch Tool, Fed funds futures imply a 47% chance of a rate increase at the U.S. Federal Reserve's policy meeting next month, down from nearly 70% last week. On Tuesday, New York Fed President John Williams said there was "no need for urgency," and signaled that the central bank may need to lift interest rates only once more this year.

The Fed in September raised its benchmark overnight interest rate 25 basis points to a range of 3.75% to 4.00%.

In Japan, investors are leaning toward a December rate hike, rather than one in October, after the Bank of Japan also raised rates 25 basis points earlier this month. Totan Research and Totan ICAP data show a 23% chance of an October increase, compared with odds of more than 80% for December.

Emerging economies such as India face their own policy dilemma as inflationary pressures build, complicating the outlook for interest rates.

While the Reserve Bank of India kept rates unchanged for a fourth consecutive meeting in August, markets now increasingly predict the central bank will raise rates in October. India relies on imports to meet around 90% of its crude oil demand.