Sri Lanka's newly elected president Mithripala Sirisena waves at media as he leaves the election commission in Colombo January 9, 2015. [Photo/Agencies]

COLOMBO - Sri Lanka's president-elect Maithripala Sirisena will be sworn in Friday night, opposition United National Party (UNP) leader Ranil Wickremesinghe said.

Sirisena, a former health minister, claimed victory in Thursday 's presidential election after incumbent president Mahinda Rajapaksa said he would ensure a smooth transfer of power at a meeting with Ranil earlier in the day.

Rajapaksa has conceded defeat in the vote and left the presidential residence.

Ranil noted that Sri Lankans respect President Rajapaksa who ended a decades-long civil war in May 2009.

"We are trying to make a change for good governance. We must allow Sirisena to take oath. The law will be implemented to the letter. I have given instructions to police." Ranil told a press conference.