A quick search defines invasive species as a type of introduced species, which is outlined as

An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there by human activity, directly or indirectly, and either deliberately or accidentally.

So I'd say that technically they are, but even more to the point it seems like the invasive species definition is very human centric (an alien cannot create an invasive species?)

They adapted the definition to include causing economic or environmental harm because NERDS kept pointing out that all species are either constantly invading new territory or in the process of going extinct.