Speaking at the end of a trade visit to China, the PM said Britain would not face a choice between a free trade deal with the EU after Brexit and striking deals with the rest of the world.
It comes as she has faced criticism from Eurosceptic Tory MPs that she is heading for a "Brexit in name only".
Asked about her future as PM, Mrs May said she was "not a quitter".
During the prime minister's three-day visit to China, Downing Street said more than £9bn of business deals would be signed.
However, Mrs May has faced growing criticism from MPs, including many in her own party, who have called for her to be more specific about her priorities on UK's future trade arrangements with the EU.
Speaking to the BBC's political editor Laura Kuenssberg, the prime minister said she had already spelled out what she wants from the deal and did not believe the UK would have to choose between Europe and the rest of the world.
"I don't believe that those are the alternatives," she said.
"What the British people voted for is for us to take back control of our money, our borders and our laws and that's exactly what we are going to do.
"We also want to ensure that we can trade across borders."
She added: "What I favour is a deal, an arrangement for trading with the European Union which is going to be good for trade between the UK and the European Union and good for jobs in Britain."
While Theresa May has been away - successfully signing trade deals - I have been assessing the battles she faces on the home front, within her own party.
What is most striking is that some who supported her have, at the very least, become wobblier. One ex-minister said he felt "badly let down". She has been accused of blocking, not delivering, radical change.
A former supporter questioned her lack of decisiveness: "She has more reviews than a film critic would produce in a lifetime."
A Remainer who despises Boris Johnson wondered if - to coin a phrase - the foreign secretary's "bad leadership would be better than no leadership".
Council candidates fear poor results in London's May elections and think this could be a trigger for the PM to go.
And a Conservative-supporting business leader felt - though he didn't advocate it - that her opponents "will pull the pin from the grenade".
Downing Street believes the feeding frenzy of speculation will abate when more progress is made on EU withdrawal. But they are aware of the challenges at home as well as abroad.
The prime minister has come under pressure from Eurosceptics worried about potential concessions by the UK in the Brexit talks.
Last week, Chancellor Philip Hammond suggested Britain's relationship with the EU would change only "very modestly" after Brexit.
However, cabinet members - including Foreign Secretary Boris Johnson - have warned the UK will lose the main advantages of Brexit if it remains bound by trade rules of the single market and customs union.
They have called for the prime minister to be clearer about her own position.