Do I need to pay income tax on the interest I earned on foreign investments?

I have an house in another country and at moment I am renting it.
Do I need to pay tax on the rental income? Do I need to declare that I own an house in another country? At moment I already paying tax in that country.
Thanks
Thanks for your answer.

Yes, I am in US and I live and work here. The house in another country and I pay already tax on the propriety and I already pay tax on the money that I earn for the renting.

Anyway, how can I found in US one rofessional tax preparer. I was thinking to use Turbotax software also.

Thanks..