Although worldwide observers reported some "issues" during the March 31 second round that saw heightened security measures, the monitors declared themselves "satisfied" with the overall conduct of the poll.
Kamara's All People's Congress (APC) had earlier on Wednesday written to the NEC demanding a recount of votes in the Southern Province - a known opposition stronghold.
The APC was the ruling party before this election.
The election marks the first time in a decade that the SLPP party has won the presidency.
SLPP officials urged the party's backers to remain calm.
Sixteen political parties contested in the elections, with more than 3.1 million voters registered across the country.
Many have described the new parliament as the best the country has ever had throughout its post-independence history
Maada Bio emerged winners after the presidential election run-off on March 31, 2018.
He also commended the immediate past president, Ernest Bai Koroma, for his commitment to a credible electoral process and spirited efforts at bringing stability and positive changes to the nation during his presidency.
Bio is a retired Brigadier in the Sierra Leone Military.
Samura Wilson Kamara, the defeated Sierra Leone's presidential candidate is heading for the court, hours after the victor, Julius Maada Bio was sworn into office. Mr. Bio was made deputy head of state then.
In the March 7 general election, neither candidate had reached the 55 percent threshold constitutionally required to win.
He later justified his actions as a way to return the country to a democratically elected civilian government and end the civil war.
He later organized elections that same year and handed over power to Ahmad Tejan Kabbah.
In a post on Facebook, he also claimed: "My departure from Freetown was not sudden and when I bid farewell to President Koroma I did not get any indication in word or deed that I was not wanted anymore in his country". His wife Fatima is a practicing Muslim, and an ethnic Mandingo from Koidu, Kono District in eastern Sierra Leone.
Carrie Underwood Fans Call out Photo for Showing Only Half Her Face
The 35-year-old country singer, a seven-time Grammy victor , has her hair in a topknot in the revealing photo. The singer said the fall left her "not quite looking the same" and was a "freak random accident".