Abd-Rabbu Mansour Hadi took the constitutional oath to become Yemen's new president on Saturday, formally removing Ali Abdullah Saleh from power after a year of protests that paralysed the impoverished Arab country.
Hadi, who stood as the sole candidate to replace Saleh in a US-backed power transfer deal brokered by Gulf neighbours, was voted in after more than 60 per cent of eligible voters had taken part in the election this week.
Saleh's departure makes him the fourth Arab autocrat to be removed from power in more than a year of mass uprisings and war that have redrawn the political map of the Middle East.
After taking the oath, Hadi said in a speech that Yemen must draw a line under the crisis and tackle pressing issues such as a deepening economic crisis, and bringing those displaced by Yemen's crisis back to their homes.
"If we don't deal with challenges practically, then chaos will reign," Hadi said.
Yemen's richer neighbours, led by Saudi Arabia, crafted the power transfer, also backed by Washington and a UN Security Council resolution, to ease out Saleh, who had ruled Yemen for 33 years. There was concern that chaos in Yemen could empower the country's branch of Al-Qaeda near oil shipping routes.
Hadi's inauguration is scheduled for Monday, which Saleh is to attend. Saleh returned to Yemen on Friday after seeking treatment in the United States for injuries suffered in a assassination attempt last year.
A high election turnout was deemed crucial to Hadi's legitimacy, but the vote was rejected in advance in wide swathes of the country, notably the south, where secessionists urged a boycott.
The pact enshrines Hadi as the head of state and key figure in a proposed two-year political transition that envisions parliamentary elections, a new constitution and restructuring of the military in which Saleh's son and nephew still hold power.