US Treasury Secretary Timothy Geithner has secured more time for Congress to negotiate a deal to increase the borrowing limit of the US. Stalemate over the talks means the US risks defaulting on its debts because it will be unable to borrow beyond its $14.3 trillion (£8.6tn) limit. Mr Geithner had previously said the deadline for a deal was 8 July. But in a letter to Congress he said that better tax receipts meant the deadline could be extended to 2 August. Republicans want to tie any agreement on the US budget to spending cuts, especially in the healthcare programme....