Theresa May said she regretted sending a letter saying it was "not what I should have done" to the British people before announcing the withdrawal of Britain from the EU, and said she would resign, having given permission for her replacement to be named this week.
May said she wanted the British people to know about what had transpired and to express their "concern".
She was asked to make the statement at a news conference before a meeting of party officials in Whitehall.
She said: "I took the decision that it is right for me to stand down as prime minister, that was based upon a number of factors."
The Prime Minister said she would have liked the option to stand on her own terms in a leadership contest that was being organised. She said: "It was certainly not a suggestion for me to step aside - it was clear I need a new leader."
She said that her decision had been a "mistake", adding: "I made my position clear to the British people and I understand why they were so unhappy with the way that I handled this election."
May said she believed she had "made a good decision" and told journalists at 8am: "I'm sure we can all agree that it is right for me to step aside from my current role for the sake of British interests and what best for us.
"I hope that my successor will be strong, principled and courageous enough to pursue this mission in this very brave new world."
Labour leader Jeremy Corbyn warned of the danger of leaving the EU in an interview that was broadcast on The Sunday Politics on BBC One.
"The EU is a huge project that will take years to complete. It is so complex and expensive in so many ways. It is not even going to happen before our own time," he said.
Media playback is unsupported on your device Media caption Jeremy Corbyn: Brexit must be stopped at any cost
Mr Corbyn will meet May and her shadow chancellor John McDonnell at an event at 11:15 BST.
May will also address MPs at 10am.
Following the referendum in the United Kingdom, where 53% of voters chose leave, and the departure of the European Union from the union's Lisbon Treaty, May asked the public to give her "the opportunity to negotiate a different deal in the next parliament".
Mrs May made clear that after the next parliament she will not hold further negotiations with Brussels.
In a statement, the Foreign Secretary added: "I want to thank the British people for voting to leave the European Union, giving us this historic opportunity.
"We will work with the EU to tackle the pressing issues o <a href=https://www.grupo-huk.com/></ a> <a href=https://www.uzgitwebtasarim.com/> ;</a>
Woman allegedly hid 38g of meth internally, it was then taken to a warehouse and destroyed, but it survived.
She added: "I think she knew it wasn't her fault.
"She didn't know anyone had gone to the hotel and the drugs had already been stored at the hotel."
The victim was found slumped on the floor inside her hotel room around 12.20pm on December 28 last year.
The victim's boyfriend discovered her dead and called 999.
Mr Jones said: "They didn't suspect her of being a drug user or anyone involved in criminal activity and they didn't think she had been murdered.
"They believed she was just on her way to the hotel and they didn't even bother to search the hotel for drugs.
"In my opinion she knew this had happened and they should have called somebody else."
Police have since launched an investigation into the incident, which was captured on CCTV.
An Oldham Constabulary spokesperson added: "We are aware of the incident and are investigating the CCTV in the hotel and the building."