ask someone "to do" something

Hi everybody:

Here’s a sentence:

“He asked me [size=150]to mail the letter.”[/size]

About the “to mail the letter” part, I wanna make sure if this is an adverb phrase modifying the verb “ask,” or is it a noun phrase being the direct object of the verb “ask.”

It confuses me a lot. I find it hard to distinguish not just in this verb, but also in “want someone to do something,” or “warn someone not to do something

Thank you very much!

It’s an infinitive phrase modifying ‘me’ as an objective complement.

Oh,you are right!!! An object complement sounds more reasonable. I think I agree with you more than my own thinking. Thank you, James.

Thank you too. We both learn.