Along with a more efficient government using its resources to help its citizens, there is a solution that needs to happen to lower the amount of debt the US government owes. It is mutual debt forgiveness. The US government owns debts of other countries, and a lot of those same countries own US debt (http://www.bbc.co.uk/news/business-15748696). It is rational for both parties to work together to forgive debt to an amount where 1 party reaches 0 government held debt on the different kinds of debt (equity, long-term, and short-term) as shown on the treasury.gov website (http://www.treasury.gov/press-center/press-releases/pages/tg1285.ASPX) . This will also allow for less overall payments, as part of this deal should include interest not having to be paid on the principle amount that was forgiven (to the point agreed upon). This will only effect debt owned by the governments of both countries involved, but that will still lower the debt by a big amount.
Note that these links show the amounts owned by both public and private sources, but they still give an idea of the scale that can be achieved through an agreement like this.