Expired passport and valid visa

[immihelp]

Dear Sir/Madam,

I have a valid visa to the US. However, the life of the passport that contains the visa has expired. I have been issued with a new passport. Do I have to apply a fresh for a new visa or what should I do given that I intend to travel to US to present at a conference?

I would really appreciate you response.

Sincerely,

[immihelp]

No, just carry both passports.