The White House said Wednesday it expects US inflation was still "elevated" in May despite guarded hopes a key data report due for release later this week will show price increases had cooled.

Consumer prices in the world's largest economy have soared by the fastest pace in more than four decades, with gas prices at the pump hitting new records daily amid the fallout from Russia's invasion of Ukraine as well as ongoing supply chain challenges due to the Covid-19 pandemic.

The Labor Department is due to release consumer price data for May on Friday, and economists expect the monthly increase to accelerate after slowing in April, when CPI posted an 8.3 percent increase over last year.

"We expect the headline inflation number to be elevated," Press Secretary Karine Jean-Pierre told reporters traveling with President Joe Biden on Air Force One.

Biden has made fighting inflation his top domestic priority, but is finding he has few tools to directly impact prices.

US President Joe Biden departs the White House in Washington on June 8, 2022
US President Joe Biden departs the White House in Washington on June 8, 2022 AFP / Brendan Smialowski

The Federal Reserve has begun raising interest rates aggressively to combat inflationary pressures, saying the goal is to sustain economic expansion while avoiding a recession.

Biden has stuck to an upbeat message about the overall outlook.

"We continue to believe that the economy can transition from what has been a historic recovery ... to stable steady growth," Jean-Pierre said.

But she acknowledged that the impact of the war in Ukraine has continued to push some prices higher, including airfares.