Rajapaksa said in a statement that his party's victory in Thursday's elections encourages the government's policies on "peace and reconciliation, reconstruction, greater infrastructure development."
"We are humbled by the size of the repeated mandates given by the people and pledge to respond, in full measure, to the trust placed in us," he said.
The United States embassy said in a statement that the election victory provides Rajapaksa a mandate to address power sharing and human rights issues. Rajapaksa has yet to follow up on a promise made after last year's defeat of the Tamil Tiger rebels to discuss a power-sharing deal with the Tamils, more than 200,000 of whom remain displaced by the war.
Rajapaksa won re-election as president in polls three months ago, riding on his popularity following the end of the decades-long civil war. His party held a majority in the outgoing Parliament.
With 45 seats still undeclared Saturday, Rajapaksa's United People's Freedom Alliance had secured 117 seats in Thursday's election
- enough for a simple majority in the 225-seat Parliament and to form a government.
It is uncertain whether Rajapaksa's coalition can secure the two-thirds majority needed to change the constitution
- which could open the way for an amendment to allow the president to serve beyond the end of his second term in 2017.
Opponents accuse Rajapaksa of stifling dissent, encouraging cronyism and corruption and trying to establish a family dynasty. Two of Rajapaksa's brothers and a son were candidates for Parliament.
But he is a hero to many ethnic Sinhalese for defeat of the Tamil Tiger rebels last year following a civil war that killed 80,000-100,000 people.
The largest opposition party, the United National Front, won 46 seats in the vote.
UNF leader and former Prime Minister Ranil Wickremesinghe conceded defeat Saturday and said he will not step down as party leader despite being blamed for a series of election losses.
