President Donald Trump has told a campaign-style rally that consumer prices are falling 'tremendously' as he sought to allay voter anxiety about the US cost of living.

In a speech at a casino in the battleground state of Pennsylvania, the president told supporters he had 'no higher priority than making America affordable again'.

But while gas and egg prices have fallen, other food is more expensive and Americans remain unhappy about the cost of housing, childcare and healthcare.

Democrats have capitalised on Trump's vulnerability on the economy in recent off-cycle votes, leaving many Republicans uneasy about next year's midterms elections.

Tuesday's event in a swing district of Pennsylvania was the first of what the White House says will be a series of campaign-like rallies aimed at bringing its economic message to voters.

But at one point in his remarks, the Republican president again portrayed concerns about affordability as a Democratic 'hoax'.

In recent weeks, his administration has removed tariffs from dozens of food products and touted its rollback of fuel efficiency standards and Trump-branded retirement accounts for children as cost-of-living fixes.

In an excerpt from an interview with Politico released on Tuesday, Trump was asked what grade he would give the economy. 'A plus-plus-plus-plus-plus,' he said.

In a sign the policy pivot might be cutting through, Trump's approval rating rose three points to 41% in a new Reuters/Ipsos poll.

But many Americans remain downbeat on the economy.

Alaina Hunt, 37, told the BBC she lost her job in April as a designer at a construction company in Oklahoma City, partly because of Trump's tariffs on steel and aluminium.

The construction sector 'really took a hard hit very early on', she said. Ms Hunt says she has applied for at least 75 jobs to no avail.

She says rising grocery bills - about $25 extra per week - have added to the strain.

In contrast, Trump supporters maintain their faith in the presidency, asserting the broader economic landscape is influenced by factors outside Trump's control.