The party “made a big mistake,” Masisi told a news conference.
“I will respectfully step aside and participate in a smooth transition process before the inauguration. I am proud of our democratic processes and respect the will of the people.”
He urged his supporters to remain calm and rally behind the new government.
Speaking to Bok on the phone, the outgoing president said: “You can count on me to always be there to give you any guidance you want.”
In his first comments to the media since the result became clear, Boko, a former human rights lawyer, said: “What happened today takes our democracy to a higher level. Now it means that we have seen a successful, peaceful, orderly democracy. transition”.
UDC and other opposition party supporters celebrated in the capital Gaborone and elsewhere in the country.
“I never thought I would witness such a change in my life,” Mpho Magarosi, a 23-year-old student who took to the streets of Gaborone, told Reuters.
“The BDP has stayed in power for too long and I am proud to be part of the people who got rid of them for a better Botswana,” she said.
As per preliminary count, UDC won 30 seats.
The party will win the largest number of seats in parliament and is predicted to break the 31-seat barrier for an absolute majority.
She pledged to adopt a new economic strategy that creates good-paying jobs and redistributes wealth that empowers all citizens.
Kgaberego Nkawana, a newly elected UDC MP, told the BBC’s Newsday program that many young people in Botswana are unemployed, despite the country’s vast diamond deposits and quite a thriving tourism industry.