It is more than a month or It has been more than a month

Which of the following sentences is correct?

1) It is more than a month that I have been waiting for a response on your part.

2) It has been more than a month that I have been waiting for a response on your part.

If both are possible, do they mean the same thing?

If so, which would you use or do you have a better way to say this?

Thank you