Newly-appointed Prime Minister Liz Truss on Tuesday promised to transform Britain into an "aspiration nation", saying she has a "bold plan" to grow economy through tax cuts and reform.

In her maiden speech as Prime Minister outside 10 Downing Street, Truss said that she is honoured to take on the responsibility at a vital time for the country.

Truss, 47, said her government will "transform Britain into an aspiration nation with high paying jobs, safe streets and where everyone everywhere has the opportunities they deserve."

She said she "will take action this day and every day to make it happen."

Asserting that she will pursue early priorities like getting Britain working again, Truss said she has a "bold plan" to grow the economy through tax cuts and reform.

Truss, who replaced Boris Johnson as the Prime Minister, promised to deal "hands-on" with the energy crisis which she said has been caused by Russian President Vladimir Putin's Ukraine war.

"Boris Johnson delivered Brexit, the Covid vaccine and stood up to Russian aggression. History will see him as a hugely consequential prime minister," said Truss, who was appointed as Prime Minister by Queen Elizabeth II following her victory over former minister Rishi Sunak in the Conservative Party leadership race.