President Hamid Karzai prepared for a second term of office on Tuesday with the US president Barack Obama telling him to wipe out corruption and world leaders urging him to unify Afghanistan. Mr Karzai was declared president for another five years after the cancellation of a run-off by the country's election commission, which followed the withdrawal at the weekend of his only challenger, Abdullah Abdullah. Mr Obama and the UN chief Ban Ki-moon led world powers in congratulating Mr Karzai, who was due to give a press conference about 10am local time today. But the US president said he had told his Afghan counterpart to make "a much more serious effort to eradicate corruption" while calling for a "new chapter" in co-operation between the two countries. "This has to be the point in time in which we begin to write a new chapter based on improved governance," Mr Obama said he had told Mr Karzai in a telephone call. Mr Karzai "assured me that he understood the importance of this moment but... the truth is not going to be in words, it's going to be in deeds," Mr Obama added. Earlier the White House declared Mr Karzai the "legitimate leader of the country" but said it would begin "hard conversations" with the new president, with Mr Obama expected to make a decision on whether to deploy thousands more troops "in the coming weeks". The former foreign minister, Abdullah Abdullah, quit the contest on Sunday, saying there were no safeguards against a repeat of widespread fraud that resulted in the throwing out of nearly a quarter of votes cast in August. Mr Karzai's anointment by the Independent Election Commission (IEC) followed intense diplomatic pressure and sought to draw a line under two months of political chaos in a war-torn nation where 100,000 Nato and US troops are battling an increasingly violent Taliban insurgency. The UN chief met Mr Karzai and Mr Abdullah amid a concerted diplomatic push to bring a quick end to chaos that has undermined Western efforts to cultivate democracy in Afghanistan eight years after a US-led invasion. IEC chief Azizullah Ludin, a Karzai appointee who oversaw a fraud-riddled first round, said the decision had been made in line with the provisions of Afghan electoral law and constitution and was "consistent with the high interest of the Afghan people". The British prime minister Gordon Brown, whose country is the second biggest contributor of foreign troops in Afghanistan, telephoned Mr Karzai to urge him to plot a course of national unity. "They discussed the importance of the president moving quickly to set out a unifying programme for the future of Afghanistan," said a spokesman for Mr Brown. Nato powers France and Germany urged Mr Karzai to work with his defeated rival to end the political strife. Congratulations also came from Pakistan and Russia, which said the election had "opened the way for the formation of the new national government, whose great task is the key problem of stabilising conditions in the country." There had been great unease about staging the November 7 poll at a time when a Taliban insurgency is gathering pace. The IEC's deputy chief electoral officer Zakria Barakzai said the commission would have been in breach of article 61 of the constitution ? which states two candidates must contest a runoff ? had they allowed the contest to go ahead without Abdullah. First-round turnout was as low as five per cent on August 20 in areas worst hit by the Taliban insurgency and with the militia threatening fresh attacks, the numbers voting this time were likely to have been even lower. Analysts said Mr Karzai, already tainted by the first round fraud, would struggle to proclaim his legitimacy in such circumstances. After Mr Karzai snubbed a series of demands promoted by his rival as a chance to avoid a repeat of massive first-round fraud, Abdullah said Sunday that he saw no point in standing, but had stopped short of calling for a boycott. * AFP