Red-hot US inflation is showing few signs of cooling, putting the Federal Reserve on track to continue its aggressive interest rate increases to help cool high prices that are challenging Joe Biden’s presidency.

The hoped-for signs of relief for American families did not materialize in May as consumer prices hit a new four-decade high, rising 8.6 percent and topping what economists thought was the peak in March.

With Russia’s war on Ukraine continuing to pressure global fuel and food prices, and amid ongoing supply chain uncertainties due to Covid-19 lockdowns in Asia, analysts now say the expected easing of inflationary pressures will take much longer to materialize.

The US central bank already had signaled plans for more big increases in the benchmark borrowing rate this week and next month, but chances are rising that the Fed might have to be even more aggressive — which increases the risk the economy might tip into a recession.

The latest inflation report — the last major data point before the Fed’s policy meeting Tuesday and Wednesday — also douses hopes central bankers will be able to call a ceasefire in September ahead of key congressional elections, where Biden’s Democrats are widely expected to suffer damaging losses.

Prices continued to rise last month for a range of goods, including housing, groceries, airline fares and used and new vehicles, setting new records in multiple categories, according to the Labor Department data.

Energy has soared 34.6 percent over the past year, the fastest since September 2005, while food jumped 10.1 percent, and the cost of fuel oil more than doubled, jumping 106.7 percent, the largest increase in the history of CPI, which dates to 1935.

The CPI surge “raises the probability of even more aggressive Fed rate hikes to tamp down on inflationary expectations,” said Mickey Levy of Berenberg Capital Markets.

If the policy-setting Federal Open Market Committee decides on a giant step –three quarters of a point rather than the expected half-point increase — it would be the first 75 basis point rate hike since November 1994.

Diane Swonk of Grant Thornton indicated such a move is possible.

“They are behind the curve and eager to catch up,” she said on Twitter. “Fed has to reduce demand to meet a supply-constrained world. Ugly in many ways.”

Economists at Barclays are now calling for a 0.75-point increase, though Ryan Sweet at Moody’s says chances are low, and Karl Haeling at LBBW expects three more half-point hikes.

Biden is facing growing political backlash as high prices increase the pain for American families, who are seeing daily records at the gas pump and higher grocery bills due to the fallout from Russian leader Vladimir Putin’s invasion of Ukraine.

Unlike his predecessor Donald Trump, who relentlessly attacked the Fed and its chair Jerome Powell, Biden has publicly endorsed the central bank’s efforts.

Biden, who blames “Putin’s Price Hike” for the acceleration in inflation, said Washington “must do more — and quickly — to get prices down here in the United States.”

Hoping to avoid a devastating setback in November elections that could return control of the legislature to opposition Republicans, Biden has urged Congress to approve legislation to bring down costs of key products such as medicines and services such as shipping to soften the blow for US consumers.

Some analysts had speculated that Powell might call for a timeout in the interest rate moves at the FOMC’s September meeting, but economist Levy echoed the prevailing view that a pause in rate hikes is now “looking increasingly unlikely.”

Powell has always insisted that central bankers eschew political considerations and focus on what’s best for the economy.

The Fed, which has already acknowledged that slowing demand will entail some pain, is hoping to cool price pressures without choking off economic growth — but that is looking increasingly difficult.

Gita Gopinath, the number two at the International Monetary Fund, last week told US central bankers are treading an “incredibly narrow path” to achieve a soft landing and avoid a sharp increase in unemployment.

“It will be a real challenge to bring down inflation… without turbulence,” she said at a Financial Times conference, adding that it could “require much steeper increases in rates.”