With just over a month to go until Donald Trump’s inauguration, the president-elect’s pick for national security adviser, Republican Representative Mike Waltz, hit out against the Biden administration’s response to the sightings.

“I think Americans are finding it hard to believe we can’t figure out where these are coming from,” he told the BBC’s US news partner CBS.

“We need to get to the bottom of it,” he said, accusing government agencies of “pointing at each other” rather than offering answers.

Kim, a Democrat, also called on federal authorities to do more to assuage Americans’ concerns.

“People have a lot anxiety right now about the economy, health, security etc,” he wrote on X.

“And too often we find that those charged with working on these issues don’t engage the public with the respect and depth needed.”