China is aiming to purge most foreign technology from banks, the military, state-owned enterprises and key government agencies by 2020, stepping up efforts to shift to Chinese suppliers, according to people familiar with the effort. The plan for changes in four segments of the economy is driven by national security concerns and marks an increasingly determined move away from foreign suppliers under President Xi Jinping, the people said. The campaign could have lasting consequences for U.S. companies including Cisco Systems Inc., International Business Machines Corp., Intel Corp. and Hewlett-Packard Co.