Addressing the island's 67th independence anniversary here that saw the country's main Tamil party TNA attend the celebrations for the first time in decades, Sirisena asked: "Can we be truly happy with our achievements since 1948?"
"All leaders must take the blame for their failures," in an apparent reference to his predecessor and two-term president Mahinda Rajapaksa, who was despised for allegedly sidelining the Tamil and Muslim minorities in order to retain his popularity with the majority Sinhalese.
"The biggest challenge today is to unite the hearts of the people of the north and south through a national reconciliation process," Sirisena said.
The LTTE, based in the northern and eastern parts of the country, were fighting for an independent state for Sri Lanka's minority Tamils.
"We ventured into massive physical development since the end of the war in 2009. But we failed to bring together the hearts and minds of communities," said Sirisena, who trounced Rajapaksa in the January 8 polls.
"All political parties and leaders who governed this country must look at themselves and meditate on their role and look to the future," Sirisena said.
Praising Rajapaksa for bringing the LTTE's separatist war to an end, he stressed the need to achieve national reconciliation by bringing all communities together.
Sirisena and his ministers also pledged in a nationally televised address to never allow the "land to be traumatised by the shedding of blood of innocents".
Vowing to duly implement his democratic and constitutional reforms, Sirisena said his government would pursue a foreign policy of neutrality to win over the international community to develop the island.
