U.S. Treasury yields climbed Monday after Federal Reserve chief Jerome Powell warned about rampant inflation.

The yield on the benchmark 10-year Treasury note rose 15.4 basis points to 2.302% by around 4:05 p.m. ET. The yield on the 30-year Treasury bond moved 10.5 basis points higher to 2.525%. Yields move inversely to prices and 1 basis point is equal to 0.01%.

Meanwhile, the 2-year yield rose above 2%, its highest level since 2019.

Powell on Monday promised to take tough action on inflation, which he said jeopardizes an otherwise strong economic recovery.

"The labor market is very strong, and inflation is much too high," the central bank leader said in prepared remarks for the National Association for Business Economics.

Powell also noted rate hikes could go from the traditional quarter-percentage-point moves to more aggressive half-basis-point increases if necessary.

"The Fed at this point really wants to project at least a willingness to move very aggressively against the rising inflationary pressures that they're facing, and that means prioritizing its response to inflation over, say, long term growth," Chip Hughey, managing director of fixed income at Truist Advisory Services, said.

Investors will be keeping an eye out for more indications on the Fed's policy plans, after the central bank raised its benchmark interest rate for the first time in more than three years last week.

Investors continued monitoring the geopolitical conflict between Russia and Ukraine.

Ukraine's President Volodymyr Zelenskyy warned that if peace talks with Russian leader Vladimir Putin fail, it would mean the start of a global war.

"If these attempts fail, that would mean that this is a third world war," Zelenskyy said in an interview with CNN's Fareed Zakaria that aired Sunday morning. Ukrainian and Russian officials have met intermittently for peace talks, which have failed to progress to key concessions.

Investors are also monitoring the rise in Covid-19 cases in Europe, stemming from an emerging variant.

"The sell-off in bond prices (which sent yields higher) occurred as investors weighed the impact of higher inflation with the war in Ukraine on US and global growth in the months and quarters ahead," John Stoltzfus, chief investment strategist at Oppenheimer, said in a note Monday.

— CNBC's Maggie Fitzgerald contributed to this market report.