having addressed his new cabinet ministers for the first time.
Boris Johnson told the cabinet they had "a momentous task ahead", as he repeated his commitment for the UK to leave the EU on 31 October.
On Wednesday, Mr Johnson gave key roles to leading Brexiteers.
The appointments saw Sajid Javid as chancellor, and Dominic Raab and Priti Patel return to government.
Mr Raab was made foreign secretary and Ms Patel is home secretary.
More than half of Theresa May's old cabinet, including leadership rival Jeremy Hunt, quit or were sacked.
BBC political editor Laura Kuenssberg said there were whispers there could be a big offer for European citizens coming out of cabinet this morning.
BBC
Russia's unmanned Luna-25 spacecraft has crashed into the Moon after spinning out of control, officials say.
Donald Trump has confirmed that he will not take part in Republican presidential debates with his rivals in the race for the White House.