SEOUL, South Korea (AP) – The United States says it will seek tougher U.N. Security Council sanctions after North Korea said it test-fired its biggest intercontinental ballistic missile to date. U.S. Ambassador Linda Thomas-Greenfield said Friday the U.S. would propose a measure “to update and strengthen” the council’s sanctions, though she didn’t specify how. But veto-wielding China and Russia have recently called instead for lifting sanctions on North Korea, citing its economic troubles. Thursday’s launch extended a barrage of weapons demonstrations this year that analysts say are aimed at forcing the U.S. to accept the idea of North Korea as a nuclear power and remove sanctions. Meanwhile, the U.S. responded to the launch by imposing new sanctions of its own. (Photo: AP)