what does it mean - i'm on it?

[Olgakost]

Hi to everyone!
Can you help me understand the meaning of such a phrase “I’m on it”
The situation was:
A friend of mine was making tea but he forgot about it for a while
I asked him to check the pot and he said – I’m on it.
He explained he had heard something like it somewhere in films… when people say that they are doing something (opening the door to look who is there and so on)
Is he right? Or it is another phrase?
Thanks a lot!!!

[Batoul Saad]

Hi, "I'm on it" is an idiom and it means "I'm handling it".

[Mansoor48]

i'm on it .. i'm doing it ....i'm on the ball .... all mean that the person shows a but of urgency in handling the task

[Olgakost]

thanks a lot!!!!!