Amid the political limbo over government formation, Indian-origin Madhesi leader Ram Baran Yadav was sworn-in as the first President of the nascent republic of Nepal on Wednesday, three days after his victory in the historic poll for the coveted post.

The 60-year-old doctor-turned politician was administered the oath of office by Chief Justice Kedar Prasad Giri at a grand function attended by some 2,000 people at the Sheetal Niwas, the office-cum residence of the new President.

"I, in the name of God take the oath of office that I will remain committed to the nation and its people to fulfil the duty with my utmost honesty and protect the sovereignty and freedom of the nation," the new President said.

Maoist chief Prachanda, who on Tuesday announced his party will sit in the opposition despite bagging the maximum seats -- but not enough to form a government -- in the landmark April 10 polls, was conspicuous by his absence at the ceremony attended by outgoing Premier G P Koirala, Army chief Rukmangad Katuwal and foreign diplomats, among others. However, Maoists' second-in command Baburam Bhattarai was present.

Yadav, the Nepali Congress-led tripartite alliance's candidate in Monday's Presidential poll run-off, defeated the Maoists-backed Ram Raja Prasad Singh by a margin of 25 votes after bagging 308 votes in the 594-member Constituent Assembly.

Attired in the traditional Nepali dress of white shirt, grey coat and black cap, Yadav assumed office amid uncertainty over the government formation following Maoists' refusal to lead the next administration in the wake of their Presidential candidate's crushing defeat, which was result of a new political equation at the eleventh hour.