|Hadi, a former army general, is the only candidate in Yemen's upcoming presidential poll [Reuters]
Abd-Rabbu Mansour Hadi, Yemen's vice-president for 17 years, faces a broad range of problems including a growing threat from al-Qaeda as he sets about his new presidential duties.
Hadi, who stood as a sole candidate in Yemen's referendum-like poll this week, ends Ali Abdullah Saleh 33-year-rule which has been rocked by street protests lasting nearly a year. His ascendency to power has seen Yemen become the first Arab Spring nation where an uprising has led to a negotiated settlement.
The single-candidate election he won this week - with 65 per cent of the voters backing him - was a condition of the power-transition deal signed by Saleh in November after 10 months of mass protests and mounting international pressure calling for him to step aside.
Under the deal, brokered by the sisx-nation Gulf Co-operation Council, Saleh transfered constitutional powers to Hadi, who he had appointed as vice-president in 1994.
Hadi, a 66-year-old former soldier from Yemen's south, was considered by most as the consensus candidate.
But two major opposition groups, the separatist Southern Movement and the northern Zaidi rebels, boycotted the poll.
The uprising's main proponents had asked Yemenis to support Hadi and posters of the vice-president were plastered across buildings and streets in the capital Sanaa.
"Hadi has local, regional and international support and is a respected leader who has a vision for the future."
- General Ali Mohsen al-Ahmar
"Hadi has local, regional and international support and is a respected leader who has a vision for the future. We call on all Yemenis to participate in the election," General Ali Mohsen al-Ahmar, whose defection last March tipped the balance in favour of the protesters, told the AFP news agency.
When news of the presidential poll came, crowds in Sanaa chanted "Hadi, take the key, the slaughterer's rule has ended."
Yemen's Nobel Peace laureate Tawakkul Karman had urged Yemenis to vote for the vice-president, saying his election would mark "the fruit of the popular youth uprising".
Hadi is expected to launch a national dialogue, the first step in the transitional period that will end in legislative and presidential elections within two years.
But many Yemenis have expressed concern over the role of the country's security forces, a major challenge Hadi will have to deal with. The forces remain under the control of Saleh's sons and nephews, and were responsible for much of the bloodshed that occurred during the crackdown on protests.
Hadi was sworn in as Saleh returned home from the US where he received treatment for injuries sustained in an attack on his palace.
Many fear his return may stock tensions but US President Barack Obama has voiced support for Hadi's new leadership.
Obama said in a letter that he looked forward to deeper relations between the two countries and promised that the US will be "a strong and reliable partner". He wrote that Yemen would become a symbol of political transformation "when people resist violence and unite under a common cause".
The letter was delivered by Obama's top counter-terrorism adviser, John Brennan, who read it to reporters in Yemen on Sunday.
Saleh's critics have repeatedly accused the veteran leader of intentionally allowing al-Qaeda to expand its influence in the country's lawless south and east to demonstrate that only he can fight the spread of terror..