SAN FRANCISCO, March 30 -- U.S. lawmakers of at least eight states are trying to mandate a "kill switch" for smartphones in an attempt to reduce smartphone thefts and robberies, local media reported on Monday.

Lawmakers in Connecticut, Illinois, Mississippi, Missouri, New Mexico, New York, Oregon and Virginia are working on bills at state legislatures to authorize introduction to newly-manufactured smartphones a software that can remotely disable stolen or lost devices, making them worthless to thieves or robbers.

California and Minnesota were the first two U.S. states to adopt rules requiring smartphone manufacturers make the "kill switch" function available in every devices. Those bills will be put into effect on July 1 this year.

Reports said last month that three cities, namely, San Francisco, New York and London, saw dramatic decline in smartphone thefts and robberies since the wireless industry began to implement "kill switch" on their devices, under Secure Our Smartphones (SOS), an international law-enforcing partnership initiative aimed at detering thefts.

Despite initial opposition from major U.S. wireless carriers, who were particularly against state level mandate for the technology, some of them are now willing to introduce similar solutions to curb phone thefts.

Lost and stolen mobile devices in 2013 were estimated to have cost U.S. consumers over 30 billion U.S. dollars.