Savannah Guthrie Believes Mother Nancy Is Still Alive, 'We Need Your Help'

Savannah Guthrie and her family are not giving up hope Nancy Guthrie is alive ... but she's desperately asking for the public's help in locating their mother.

In the 'Today' host's latest video, posted Monday afternoon, she appears alone and says they believe their mother is feeling the love and prayers from the public.

While she expresses gratitude, it also seems they haven't heard anything else from the kidnappers ... and the investigation isn't uncovering enough information.

She says law enforcement is working tirelessly, but they need someone to come forward with more information. She pleads, "No matter where you are, even if you're far from Tucson ... we are in an hour of desperation, and we need your help."

Savannah added, "God is lifting her even in this moment, in this darkest place."

The final deadline to pay the alleged ransom in the kidnapping expires at 5 PM Arizona time today. Nancy and her siblings said they will pay the $6 million bitcoin ransom ... so far today, there hasn't been any movement on the bitcoin account, which still has a balance of zero.

As you know, 84-year-old Nancy was abducted early in the morning of Feb. 1 ... she went out to dinner Saturday night, but missed church the next morning.

In a statement released Sunday, the Pima County Sheriff's Department posted, "The Nancy Guthrie investigation is ongoing. Follow-up continues at multiple locations. No suspects, persons of interest, or vehicles have been identified."