U.S. President-elect Donald Trump’s incoming national security adviser says it’s time to figure out where dozens of unexplained drones flying over eastern U.S. states are coming from and whether any ill intent is involved. Republican Representative Michael Waltz, from Florida and set to join Trump’s White House team when the president-elect takes office January 20, told CBS’s “Face the Nation” on Sunday, “We need to get to the bottom of it.” For weeks now, residents in the state of New Jersey, which borders New York City, and other states to the north and south along the Atlantic Ocean coastline have reported seeing more than 5,000 supposed drones, a figure U.S. officials have concluded is wildly inflated. All manner of conspiracy theories has been offered for the unexplained sightings, including U.S. government spying and the deployment of Iran-launched drones from a mothership off U.S. eastern coastal waters. Waltz called them “long-loitering, could-be dangerous” drones. He credited the outgoing administration of President Joe Biden for trying to allay fears and resolve any mystery about the drones but offered no explanation himself. “We need more transparency,” Minnesota Senator Amy Klobuchar, a Democrat, told the CBS show. “This can’t be the future.” On Saturday, officials from the White House, the Department of Homeland Security and the Federal Bureau of Investigation stressed that most of the recent purported drone sightings in New Jersey — the state with the most reports — and elsewhere have been manned aircraft and posed no national security threat. An FBI official told reporters that the agency was working with 50 local, state and federal partners and had determined that fewer than 100 of the more than 5,000 reported sightings had turned out to merit further investigation. “The combination of efforts so far … to include technical equipment, tip line information and noted consults has … not found any evidence to support large-scale [unmanned aerial system] activities,” the official said, adding that many of the sightings occurred along regular flight paths. The official said more investigations are under way to look at the remaining cases, including analysis of radar and intelligence. “We can’t ignore the sightings that have been there,” the official said. “We’re doing our best to find the origin of those drone activities, but I think there has been a slight over-reaction” in the number of claimed drone sightings. U.S. officials say they have confirmed drone sightings over military bases in New Jersey, including Picatinny Arsenal, but found no evidence that a foreign government had launched the drones. National security officials, however, have not been able to figure out who has been operating the unexplained drones. State and local officials in eastern seaboard states have expressed concern. Larry Hogan, a former Maryland governor, posted on social media Friday that he had seen “what appeared to be dozens of large drones in the sky” above his residence in the state. “The public is growing increasingly concerned and frustrated with the complete lack of transparency and the dismissive attitude of the federal government.” President-elect Trump suggested Saturday that the Biden administration was withholding information about the drone sightings and that the devices should be shot down. Republican Representative Christopher Smith of New Jersey said Friday in a statement that the White House’s attitude toward the sightings had been “dismissive.” U.S. officials said Saturday the administration had sent New Jersey officials radar technology with an “electro-optical infrared camera system” to track the devices. Last week, White House National Security spokesperson John Kirby said an investigation of the drone sightings had not turned up any illegal activity. “To the contrary, upon review of available imagery, it appears that many of the reported sightings are actually manned aircraft that are being operated lawfully,” Kirby said.