(CNN)The Biden administration is canceling another slate of border wall contracts -- this time, in the Laredo and Rio Grande Valley sectors, the Department of Homeland Security announced Friday.... ...In late July, US Customs and Border Protection terminated two border wall contracts in the Laredo sector that cover approximately 31 miles. DHS said Friday it will cancel all remaining border barrier contracts in that sector. "CBP will then begin environmental planning... ...Since 2017, more than 450 miles have been built in multiple locations along the US southern border, including roughly 52 miles where no barrier previously existed, according to US...