Conservative leader David Cameron became Britain's youngest prime minister in almost 200 years after Gordon Brown stepped down and ended 13 years of Labour government, AP reported.
Cameron said on Tuesday that he aims to form a full coalition government with the third-place Liberal Democrats after his Conservative Party won the most seats but did not get a majority in Britain national election last week.
The 43-year-old leader said it would be "hard and difficult work" to govern as a coalition but added that Britain had serious economic issues to tackle. Cameron visited Buckingham Palace and was asked to form a government by Queen Elizabeth II less than an hour after Brown tendered his resignation to the monarch.