US news anchor Savannah Guthrie has issued a new plea for help as the reported deadline for a ransom payment for her mother's safe return loomed.

We are at an hour of desperation, and we need your help, she says in the video posted on Instagram on Monday afternoon.

Nancy Guthrie disappeared in the middle of the night from her home in Tucson, Arizona, and was last seen on January 31. Authorities believe she was taken against her will. The FBI is offering a $50,000 (£36,000) reward for information.

The family had earlier indicated that they would be willing to pay for her safe return. A previous alleged deadline for ransom, which is meant to be paid in Bitcoin, passed on February 5.

Nancy was discovered missing when she did not attend a Sunday church service on February 1, raising concerns among other members.

The family has released three previous videos addressing the potential kidnapper and requesting proof of life for their mother.

In her latest message, Savannah, appearing alone for the first time, expresses her overwhelming fear and grief. She requests help from the public, encouraging those far from Tucson to report anything suspicious that could lead to clues regarding her mother’s whereabouts.

The authorities have stated that no suspects or vehicles have yet been identified. The FBI is also examining ransom notes sent to local media outlets, which included a deadline for payment.

Despite the distressing circumstances, Savannah expresses gratitude for the public's prayers and support, emphasizing the profound impact they may have on her missing mother.