LONDON — Rishi Sunak, who will be the UK's next prime minister after winning the Conservative Party leadership contest, pledged to serve with integrity and humility.

"I pledge that I will service you with integrity and humility," Sunak said. In a brief statement, he warned the country faces "profound economic challenges".

Sunak said he is "humbled and honored" to have the support of his fellow MPs and be elected leader.

"It is the greatest privilege of my life to be able to serve the party I love and give back to the country I owe so much to."

Sunak will become the UK's first British Asian premier and at 42, the youngest leader in more than two centuries

He is the country's 57th prime minister and the UK's youngest PM since Lord Liverpool came to office in 1812.

He is the fastest from being first elected as an MP to becoming PM in modern times, taking just seven years.

Assuming the handover happens Tuesday, Liz Truss will have been prime minister for seven weeks, or 49 days.

Immediately after being selected by Tory MPs he ruled out an early general election and warned his party they had to "unite or die".

The ex-chancellor who oversaw the nation's finances during the COVID pandemic was the only contender to gain enough support from MPs.

His rival Penny Mordaunt dropped out of the race in the final minutes before nominations closed.

In his short statement he stated, that he would work day in day out to "deliver for the British people".

Sunak said the UK is a great country but faces "profound" economic challenges. He called for stability and unity.

In his short speech, Sunak’s first as the new Conservative leader and the next prime minister of the UK, he paid tribute to his predecessor Liz Truss.

A spokesperson for Truss said she would remain in Downing Street for at least another day, and that there would be no transition of power Monday.

Opposition parties have greeted Sunak's victory with fresh calls for an early general election — something the incoming PM has been quick to rule out

Sunak — after his first televised address as Tory leader — left Conservative HQ smiling and with a wave to the small crowd that had gathered.

There were shouts from the crowd of "happy Diwali".

A few minutes earlier, one Conservative MP leaving the building said: "We have a grown up in charge now."

Another said: "At last I can look my constituents in the eye and say I can back what the government says."

And yet another commented: "There is a groundswell of optimism in the party now".

Scotland's first minister Nicola Sturgeon earlier tweeted her congratulations to Sunak. She pledged to build a "constructive working relationship" with the new PM.

She said the fact he will become the first British Asian to become PM is a genuinely significant moment. However, she reiterated her calls for a general election. — BBC