Many dignitaries are set to attend Uhuru's swearing in ceremony in Nairobi
"Tuesday was an historic day for Kenya, with millions of Kenyans turning out to vote in the general election. The United Kingdom warmly congratulates President Kenyatta on his re-election," Foreign Secretary Boris Johnson said in a statement late Saturday.
"We commend the people of Kenya for their commitment to democracy and salute those who worked tirelessly and courageously towards holding credible elections, often in difficult circumstances,” he added.
The defeated opposition NASA coalition insisted they would not stop their bid to overturn the election result, which sparked violent protests that have left 11 people dead.
"We join the Kenyan people in mourning those who have died, calling on those with influence to exercise restraint at this difficult time to ensure calm, and to honour the Kenyans who turned out in such number to vote to determine their future," said Johnson.
Britain is the former colonial power in Kenya and Johnson said he looked forward to building on the strong relationship between London and Nairobi.
Meanwhile, President Uhuru Kenyatta re-election has been officially gazetted by IEBC as plans to swear him in take shape in Nairobi.