New Sri Lankan President Maithripala Sirisena has begun assembling a cabinet on his first day in office as he looks to deliver on pledges to improve the war-torn country's diplomatic standing and implement democratic reforms.  Sirisena, who was sworn in on Friday evening after a shock election victory over veteran strongman Mahinda Rajapakse, was trying to form a "national unity" cabinet that would include members from a cross section of political parties in parliament, an aide said.  "The main task is to choose a cabinet and the work is already underway," Nishantha Warnasinghe said.  Sirisena had offered a 100-day program to carry out urgent political and economic reforms, including moves to cut back on the powers of the president which Rajapakse had handed to himself during a decade in office.  Shortly after being sworn in, Sirisena appointed as new prime minister the parliamentary opposition leader Ranil Wickremesinghe, who is expected to wield considerable power.  In a public address soon after being sworn in, Sirisena promised to mend Sri Lanka's ties with the rest of the world.  "We will have a foreign policy that will mend our ties with the international community and all international organisations in order that we derive maximum benefit for our people," he said.  "We will work with friendship and brotherhood and co-operation with all states."  Rajapakse fell out with some countries over allegations his troops killed 40,000 Tamil civilians at the end of the civil war.  He refused to co-operate with a UN-mandated investigation.  Sirisena, a former health minister who united a fractured opposition to pull off an unlikely victory, thanked his predecessor for a "fair election that allowed me to be the president".  He was elected with 51.28 per cent of the votes, to the former leader's 47.58 per cent.  Sirisena has promised sweeping reforms of the presidency and said he will transfer many of its executive powers to parliament within 100 days.  He said he would serve only one term after being elected on a tide of resentment against Rajapakse.  The former leader rewrote the constitution after his re-election in 2010 to remove the two-term limit on the presidency and give himself more powers over public servants and judges.  Do you have any news photos or videos?
Maithripala Sirisena has been sworn in as Sri Lanka's new president following the surprise ousting of strongman leader Mahinda Rajapakse.