US news anchor Savannah Guthrie has posted a video message tearfully pleading for the return of her abducted mother and seeking proof from her captors that the 84-year-old is still alive.

We want to hear from you and we are ready to listen, the NBC host says, flanked by her siblings in the clip posted to Instagram. Please reach out to us.

Nancy Guthrie went missing in the middle of the night from her home in the US state of Arizona over the weekend. Authorities suspect she was kidnapped and are working with the FBI to authenticate a possible ransom note.

We are ready to talk, said the NBC host in the video posted on Wednesday night. However, we live in a world where voices and images are easily manipulated. We need to know without a doubt that she is alive and that you have her.

It is standard procedure in hostage and kidnap cases for negotiators to demand proof of life from abductors. It is unclear if Nancy Guthrie's children were directed to do so by authorities.

Pima County Sheriff's Office said they were still speaking with anyone who had contact with Nancy Guthrie last weekend, and that no suspect or person of interest had so far been identified. Savannah Guthrie, joined by her sister Annie and brother Cameron, mentioned they were aware of an alleged ransom note sent to at least one media outlet.

Officials have warned Nancy Guthrie could be in dire health without her medication. Savannah Guthrie emphasized, Her health, her heart is fragile. She lives in constant pain and needs medicine to survive and not suffer.

Savannah and her family are urging anyone with information to come forward. Shortly after her heartfelt plea, US President Donald Trump pledged federal assistance in the investigation.

The search for Nancy Guthrie involves local law enforcement and the FBI, with extensive resources being deployed to locate her. The community has rallied in support, holding gatherings and prayers for her safe return.