CNN– The White House said Monday that recent “enhanced radar capabilities” may partially explain why more objects have been detected in the US airspace.

John Kirby, National Security Council coordinator for strategic communications, explained during a White House press briefing that since the Chinese balloon program’s “recent incursion into our airspace the United States and Canada — through (North American Aerospace Command) NORAD — have been more closely scrutinizing that airspace, including enhancing our radar capabilities.”

The White House official said that it’s difficult for radar to pick up small objects, including one the size of the Chinese balloon on radar and that there are also non-military objects that are used in US airspace for scientific purposes.

On the objects that were shot down over the weekend Kirby added, “Because we have not been able to definitively assess what these most recent objects are, we acted out of an abundance of caution to protect the security, our security, our interests, and flight safety.”