The United States and Kazakhstan signed an agreement Friday opening new air transit routes for US troops and supplies flying to Afghanistan, the State Department said.The agreement enhances a United States-Kazakhstan arrangement, under which the United States began transit flights to Afghanistan across Kazakhstan?s airspace in 2001,it said in a statement.By providing access to new transit routes, Kazakhstan is providing valuable support to the international effort to defeat the violent extremism in Afghanistan and to ensure Afghanistan?s and the region?s security,it said.The deal signed in Washington by Andrew Shapiro, assistant secretary of state for political-military affairs and Erlan Idrissov, Kazakhstan?s ambassador to Washington, permits US polar routes to Kazakhstan, Shapiro’s office said.The move saves time and fuel for the aircraft involved, it added in an e-mail exchange.The deal permits both US military flights and commercial contract flights, it added.