Afghan President-elect Ashraf Ghani is set to be inaugurated in a ceremony at the presidential palace in Kabul.
It comes after six months of deadlock amid a bitter dispute over electoral fraud and a recount of votes.
Under a US-brokered unity deal Mr Ghani got the presidency and runner-up Abdullah Abdullah can nominate a figure with prime-ministerial powers.
The Taliban have described the deal as a "US-orchestrated sham" but Mr Ghani hailed it as a "big victory".
Mr Ghani praised the country's "first democratic transfer of power" and has also spoken warmly of his rival, and now partner in government, Mr Abdullah.
Mr Abdullah will be at the swearing-in along with up to 100 other dignitaries.
Mr Ghani spoke about the unity deal last week, calling for Afghanistan to build its own economy and appealing to his fellow Afghans to help eliminate corruption.
US Secretary of State John Kerry helped to broker a comprehensive audit of all eight million votes in the election earlier this year after the results were disputed.
The audit was completed this month but the final tallies and the official result have not been made public amid fears over unrest.
Afghanistan's election commission confined itself to declaring Mr Ghani the winner in a statement earlier this month.
Both sides had accused the other of fraud following the election and months of uncertainty have damaged the economy and heightened insecurity.
On Friday the Taliban overran a strategic district in the eastern province of Ghazni, highlighting some of the many challenges facing Mr Ghani and his security forces.
The US has meanwhile said that it hopes a key bilateral security agreement with Afghanistan can be signed in the coming weeks.
Source: BBC