(Reuters) -- The Senate on Thursday approved funds to pay for President Obama's Afghanistan troop increase, but refused to sign off on billions in extra nonmilitary spending sought by the House of Representatives.

The move sent the legislation funding the U.S. troop surge back to an uncertain future in the House, where lawmakers in growing numbers are demanding a clearer exit plan from Afghanistan after nine years of war.

The Obama administration in February asked for $33 billion to pay for the 30,000 increase in troops for Afghanistan that the president announced last December.