Several ministers lost their seats in Thursday's election, which saw the Conservatives lose their majority in Parliament. As May struggled to contain the fallout, her two closest aides resigned. Johnson - a former Tory leadership contender - denied he was planning a leadership challenge. But Johnson said he backed May.
May shrugged off suggestions her days in Downing St. were numbered.
Gavin Barwell was named new chief of staff.
Theresa May's party lost the majority they had and are now reaching out to a socially conservative party called the Democratic Unionists to try to form a government.
The change was unlikely to significantly quell unrest within the party.
A YouGov poll for the Sunday Times newspaper found 48 % of people felt May should quit while 38 % thought she should stay.
After an initial round of discussions, Downing Street had said on Saturday that the "principles of an outline agreement" had been agreed with the DUP. That means the DUP would back the government on confidence motions and budget votes, but it's not a coalition government or a broader pact.
It said the campaign failed to get "Theresa's positive plan for the future across" or "notice the surge in Labour support, because modern campaigning techniques require ever-narrower targeting of specific voters, and we were not talking to the people who made a decision to vote for Labour".
Theresa May remains under pressure ahead of DUP talks
That means it will support a Conservative minority government on key votes in parliament without a formal coalition deal. This is expected to mean a softer Brexit negotiating position than may have been the case under a Conservative majority.
The surprising outcome, which sent the pound tumbling, forced May to form a minority government, leaving her reliant on a small group of Northern Irish parliamentarians, just nine days before Britain is due to begin negotiating a deal to leave the EU. It aligns London more closely with the pro-British side in the divided province, where a power-sharing government with Irish nationalists is suspended.
The turmoil engulfing May has increased the chance that Britain will fall out of the European Union in 2019 without a deal.
May said that "I want to reflect on the election and why it did not deliver the result I hoped for".
Her party is deeply divided over what it wants from Brexit. They're worth about £350m a year.
Clearly, the general election result was a huge disappointment.
The pound on Friday fell 1.7% against the USA dollar and 1.4 % against the euro. She confirmed this to German leader Angela Merkel in a phone call on Saturday.
Whilst much has been made of the differences between the DUP and the Conservatives on social issues, on taxation and spending issues there are also significant issues between the two sides and it is hard to predict how they will find common ground to form a government.
The "other leader" of the moment, of course, is Labour Party chief Jeremy Corbyn, who masterfully channelled his long experience of engaging freely with the public to underscore a subtle contrast in leadership style compared to Ms.
Leaked NSA report highlights deep flaws in US elections
VR Systems says it was alerted to the danger by a client, and the company advised its clients not to open the suspect email. Amber Smith of the Osceola County Supervisor of Elections Office said her office did not receive the phishing email.
In a WhatsApp message to Conservative lawmakers, Johnson said: "Folks we need to calm down and get behind the prime minister".
Defence Minister Michael Fallon said on Sunday the cabinet would meet "early next week". The reason for the disappointing result was not the absence of support for Theresa May and the Conservatives but an unexpected surge in support for Labour.
The Times newspaper's front page declared that Britain was "effectively leaderless" and the country "all but ungovernable".
The alliance makes some modernizing Conservatives uneasy.
There was no mention of what concessions the DUP may have asked for, amid growing concern about the influence of a party opposed to abortion and gay marriage, and which has proved hugely controversial in the past over the homophobic and sectarian views of some of its representatives. The DUP won 10 seats.
She has said she favours retaining the greatest possible level of access to Europe's single market.
In an indication of the unease within the party about the link-up with the DUP, Scottish Tory leader Ruth Davidson said she had demanded a "categoric assurance" from the Prime Minister that gay rights would not be affected by a deal.
Pokken Tournament DX for Switch features local multiplayer, 3v3 battles, ranked play
Kind of a bummer, but hopefully Nintendo will have some big announcements for a traditional Switch Pokemon game coming soon. The titles, Ultra Sun and Ultra Moon , unveiled Tuesday during a special Pokemon-focused Nintendo Direct press conference.