Liz Truss has said Britain can "ride out the storm" as she took possession of the keys to Downing Street.
Truss became the fourth Tory prime minister in seven years on Tuesday after travelling to Balmoral to meet the Queen.
Her speech held outside the famous black door of Number 10 was almost forced inside as a heavy downpour hit the capital.
The clouds cleared for her to make a short address before she entered the building for the first time as prime minister.
Truss began by paying tribute to her predecessor Boris Johnson, before acknowledging the economic headwinds buffeting the nation.
She said: “I’m confident that together we can ride out the storm, we can rebuild our economy and we can become the modern brilliant Britain that I know we can be.
“This is our vital mission to ensure opportunity and prosperity for all people and future generations. I’m determined to deliver.”
Truss said she had three key goals as PM.
Firstly she said she would "get Britain working again" with tax cuts to help build the economy.
She then said she would deal "hands-on" with the looming energy crisis, promising to announce her measures to tackle it later this week.
The NHS was next on her list - with Truss promising people would be able to get doctors appointments and access services they need.
Snap polling by YouGov revealed two-thirds of Brits say they have no confidence (38%) or not very much confidence (29%) that Truss will have the right policies to tackle the issue.
Just 2% have a lot of confidence and 17% have some confidence in her strategy.
Separate polling by has YouGov found 74% of Brits think the cost of living should be the new prime minister's biggest priority.
Truss' first major intervention will be delivering a package of support for households struggling with energy bills, which are set to soar even higher next month.
The Times reports she plans to freeze energy bills for all households and businesses in order to avoid families being pushed into destitution and companies collapsing en masse.
A government source confirmed the report that the energy freeze will be around the £2,500 mark, although an insider in the Truss camp said “nothing is finalised yet”.
The plan is based on the current £1,971 energy price cap plus the £400 universal handout announced under Johnson’s government.
Help is also expected for business customers struggling with soaring bills which are not covered by the existing energy price cap in England, Scotland and Wales.
Treasury Chief Secretary Simon Clarke, a close ally of Truss, declined to give details of the package, which is expected to be announced as soon as Thursday.
He said it would “come very shortly” and “there is a clear commitment to rise to the level of events and to provide early certainty to families and businesses that there will be help available to meet the undoubted challenges that this autumn and winter are going to bring”.
He told BBC Radio 4’s Today: “It will be a major moment I think in terms of drawing a line under the sense of uncertainty which undoubtedly is present in the country at this time.”