The selloff in global bonds gained traction on Tuesday, pushing the 10-year U.S. Treasury yield to its highest level since 2007 after it rose above 5% for the first time in almost three years on Monday.

Investors accelerated selling of other global bonds too, pushing yields on 10-year German and Japanese government bonds to multiyear highs.

The 10-year Treasury yield hit a high of 5.041%, Tradeweb data showed, as heightened tensions in the Middle East fueled concerns over energy prices and inflation, leaving a quarter-point Federal Reserve rate hike on Wednesday looking close to certain. The 30-year Treasury yield also reached its highest since 2007 at 5.401%.

The 10-year German Bund yield rose to 3.572%, the highest since 2009, while the 10-year Japanese government bond yield hit a 30-year high of 3.036%.

"Rates markets remain hostage to oil and geopolitics ahead of Wednesday's Federal Open Market Committee [meeting]," Evelyne Gomez-Liechti, multiasset strategist at Mizuho, said in a note.

Any brief optimism around Iran diplomacy on Monday proved short-lived and U.S. Treasurys were then sold as oil prices began to rise again.

Whether the Federal Reserve raises interest rates or not, the 10-year Treasury yield is vulnerable to further increases due to concerns about inflation, ING rates strategists said in a note.

"Markets are clearly getting nervous, which means any setback can trigger material moves...with oil jumping higher every day and European gas trading well beyond previous highs, we see plenty of risks ahead."

Investors will be watching the Fed's comments closely, and they could help to calm bond markets, said Laura Cooper, global investment strategist at Nuveen.

If Fed Chairman Kevin Warsh signals that the committee is willing to take action to ensure price stability, this could in turn help to stem the selloff in long-end Treasurys, she said.

"At a time when the tinkering of Treasury buybacks risks eroding confidence, there is a greater need for the Fed to show resolve," she said.

The U.S. Treasury recently increased the volume of long-end debt buybacks to at least $4 billion per operation from $2 billion following a jump in long-dated government-bond yields.

It isn't just the Fed that is expected to hike interest rates as oil prices rise sharply. The European Central Bank raised interest rates last week and the Bank of Japan is expected to increase rates on Friday.

Supply disruptions in the Middle East amid heightened geopolitical tensions have kept oil prices elevated, sustaining concerns over persistent inflation and strengthening the case for tighter monetary policy, BankPro's Paolo Broccardo said in a note.

With a Fed hike widely expected, focus will switch to the voting split and, in particular, Chairman Kevin Warsh's stance, he said.

"A unanimous hike accompanied by signals of further tightening could push yields higher and extend the dollar's advance."