However, this put her on a collision course with Joe Biden, the US president, with whom she will hold her first official meeting on Wednesday.
He tweeted: “I am sick and tired of trickle-down economics. It has never worked. We’re building an economy from the bottom up and middle out.”
On Tuesday, Ms Truss confirmed that she plans to scrap the NI rise and proposed corporation tax increases, telling the BBC: “I’ll always work to make sure that we are helping those who are struggling.
“That’s why we took the action that we took on energy bills, because we didn’t want to see households facing unaffordable bills. And that’s why we’re going to take the action on National Insurance, reversing that increase as well.
“So, yes, we do have to take difficult decisions to get our economy right. We have to look at our tax rates. So corporation tax needs to be competitive with other countries so that we can attract that investment.”
Speaking to reporters on the plane to New York on Monday night, Ms Truss said: “Lower taxes lead to economic growth; there is no doubt in my mind about that.
“Having the highest taxes in 70 years and putting up corporation tax at a time when we’re trying to attract investment to this country isn’t going to deliver growth. We need to be competitive.”