The UK is on the verge of a "new chapter" in its history, Boris Johnson has said, as he promised to "finish the job" by delivering Brexit within weeks.
In his new year message, the prime minister said he hoped the country would "move forward united" after it leaves the EU on 31 January.
He vowed to govern "for everyone", not just those who backed him at the polls.
And he said he wanted more prosperity and fairer opportunity to be the hallmarks of a "remarkable" new decade.
Boosting resources for the NHS, improving the UK's infrastructure, tackling violent crime and protecting the environment were among his government's other main priorities for the year ahead, he said.
Mr Johnson, who is currently on holiday in the Caribbean, said the "first item on his agenda" when he returned was delivering on the mandate of the people and taking the UK out of the EU.
He said: "We can start a new chapter in the history of our country, in which we come together and move forward united, unleashing the enormous potential of the British people."
The Conservatives' resounding election victory on 12 December had "driven an electoral bulldozer" through the deadlock in Parliament, he said, and offered a way out of the "division, rancour and uncertainty" surrounding the Brexit debate since the 2016 referendum vote.
Legislation to ratify the withdrawal agreement with the EU easily cleared its first hurdle before Christmas, when MPs backed it by a majority of 124.
Deal 'in the microwave'
With an 80-seat Conservative majority in the Commons, the remaining stages of the bill are expected to be completed quickly in January in time, the PM said, to "get Brexit done before the end of this month".
"That oven-ready deal I talked about so much during the election campaign has already had its plastic covering pierced and been placed in the microwave," he said.
While the UK is set to leave the EU's institutions at 23.00 GMT on 31 January, negotiations over its future economic relationship with the 27-member bloc have yet to begin, with experts saying they will be far tougher than those over the terms of the UK's exit.
Mr Johnson has set himself a deadline of completing an ambitious trade deal by the end of 2020, when the 11-month transition period agreed by the two sides ends. Many leading EU figures have cast doubt upon the tight timetable and questioned the PM's ruling out of any extension.
Mr Johnson has pledged to put public services at the heart of a One Nation agenda, promising billions of extra investment for the NHS in the next four years and levelling up schools funding across England.
Ahead of what is traditionally the most difficult time of the year for the health service, Mr Johnson insisted it was his "top priority" and his ambition was to provide "state of the art" healthcare which remained free at the point of use.
"The loudest message I heard during the election campaign is that people expect us - expect me - to protect and improve the NHS."
'Prime minister for everyone'
He said he aimed to deliver a "people's government".
"I am acutely aware that there are millions of people who did not vote for me and were disappointed by the result," he said.
"If you are one of them, I want to reassure you that I will be a prime minister for everyone, not just those who voted for me. I know that you love this country no less, simply because you voted for another party or wanted to Remain."
Mr Johnson, who a year ago was languishing on the backbenches after quitting Theresa May's government, is said to be planning a major cabinet reshuffle and departmental reorganisation after the UK leaves the EU.
He has also signalled that infrastructure and science will be at the heart of a Budget in March, with the aim of making the UK "an engine for the ideas of the future".
He said he wanted to "make the 2020s a decade of prosperity and opportunity" with a "fantastically exciting agenda".
'Mitigate the worst'
In his new year message, Jeremy Corbyn has insisted Labour will remain the "resistance" to Boris Johnson's government despite their heavy defeat while the SNP's Nicola Sturgeon said leaving the EU was a source of "deep regret" for many Scots and her government would do all it could to "mitigate the worst impacts".
Elsewhere, Nigel Farage has said he is in no rush to make any decision about the Brexit Party's future. He told supporters that the party had "changed politics for good", despite failing to elect any MPs after it decided not to field candidates in more than 300 Conservative-held seats.
"Don't let anyone tell you that we have not succeeded in our main goals," he wrote in an email. "We are now assessing thoughts and ideas as to what our next steps might be."