British English has many short phrases for taking a problem on oneself.
I’ll sort it: I will deal with it myself.
Consider it done: The matter is in hand and needs no more thought.
To crack on: To get on with the work without waiting.
To get stuck in: To start work with energy.
To use one’s initiative: To act on one’s own judgment without being told.
Not my department: It is someone else’s problem. The phrase is usually said with disapproval.