Homeland Security Secretary Alejandro Mayorkas suggested that the mysterious drones reportedly spotted in the skies of New Jersey and around the country are not "nefarious" nor a "threat." "We know of no threat or nefarious activity, and I want to repeat, Wolf, that if we learn of any cause for concern, we will be transparent in our communication," Mayorkas told CNN's Wolf Blitzer Friday. His response comes as there have been mounting reports of sightings in New Jersey, New York and, according to Philadelphia’s WPVI-TV, multiple reports of flying objects within Delaware and Philadelphia counties. The Pentagon on Wednesday denied that any foreign country was behind the mysterious drones that have flown near sensitive U.S. military sites in New Jersey. President-elect Trump on Friday evening called for authorities to shoot down the mysterious drones that have been seen in the skies of New Jersey and around the country. When asked about his response to Trump's request, Mayorkas reiterated that they have not seen anything "unusual" nor is there any "threat." "We can't just shoot a drone out of the sky," Mayorkas said, after underscoring that their authority is "very limited." "We have gone to Congress repeatedly asking for more authority to counter drone activity, and we have also asked for more authority to give to the state and local officials under our supervision, because it correctly notes those authorities need to be expanded," Mayorkas said.