Global bond yields have climbed to their highest point in nearly two decades, fueled by rising oil prices that have intensified inflation concerns and a significant market repricing of anticipated Federal Reserve interest rate hikes.

Tracking the selloff in US Treasuries, Japanese and Australian bonds weakened on Tuesday, with the 10-year US Treasury yield reaching its highest level since January of last year. The Bloomberg Global Aggregate Government Bond Index rose for a fourth consecutive session on Monday, hitting 3.72%, a peak not seen since mid-2008.

The immediate catalyst for the upward yield movement was Friday's speech by Federal Reserve Chair Kevin Warsh at the Jackson Hole symposium. He reiterated his determination to end a five-year stretch of inflation running above the central bank's target. Adding to the pressure, renewed conflict between the US and Iran has stoked worries that energy shipments through the Strait of Hormuz could face prolonged disruptions, driving oil prices higher.

"The market is pricing in that short-term rates in the US and globally will stay at elevated levels for longer," said Idanna Appio, portfolio manager and senior research analyst at First Eagle. "Investors are beginning to reassess the appropriate range for the neutral policy rate, and expectations for that rate have been steadily moving upward."

Concerns over significant fiscal spending in major economies, including Japan, the UK, and the US, have also prompted investors to demand a higher risk premium for holding long-dated bonds. The 10-year Japanese government bond yield surpassed 3% for the first time since 1996 on Tuesday, while the yield on the same-maturity Australian government bond surged to levels last seen in 2011.