The search for Savannah Guthrie's missing mom, Nancy Guthrie, has grown. NBC News reported on Wednesday, February 4, that the FBI is now involved in the investigation, which also includes about 100 detectives from the sheriff's office. The outlet also reported that President Donald Trump reached out to Savannah, 54, after an interview with NBC Nightly News anchor Tom Llamas to assure the family that every resource was available as needed. Trump, 79, shared on Tuesday that he would commit to sending more federal agents to aid the search. Llamas, 46, claimed that Savannah thanked Trump for the phone call and noted that the family is praying. Donald Trump Reacts to 'Terrible' Disappearance of Savannah Guthrie's Mom Nancy was initially reported missing on Sunday, February 1, by a family member who called 911. Nancy's daughter Annie Guthrie was the least person to see her, according to Pima County Sheriff Chris Nanos. (Nancy shared daughters Savannah and Annie and son Camron with late husband Charles, who died at age 49 after a heart attack.) "We have a start point," Nanos exclusively told Us Weekly. "The family took her home from dinner at about 9:30 to 9:45 [p.m.] So we would back that up to even say 9 or 8:30 p.m. to start looking." Getty Images Nanos claimed that Annie didn't raise any "red flags" about Nancy's behavior before her disappearance. He alleged that family members "weren't alerted to her [missing] until about 11 in the morning" the following day, with police being called around 12:15 p.m. Authorities are investigating a timeline "anywhere from 9:30 p.m. to 11 [a.m.]" as the window of when Nancy went missing. "This is an 84-year-old lady who is safe in her own home asleep, and she is taken. That should never happen," Nanos told Us, noting that Savannah's mom takes medication and "going without her meds can be fatal." Savannah Guthrie's Mom Nancy's Search Mission Is a 'Race Against Time' On Wednesday, the sheriff's department shared that they have not identified a suspect despite an unverified report to the contrary. "At this point, investigators have not identified a suspect or person of interest in this case. Detectives continue to speak with anyone who may have had contact with Mrs. Guthrie," a statement from the department read. "Detectives are working closely with the Guthrie family. While we appreciate the public's concern, the sharing of unverified accusations or false information is irresponsible and does not assist the investigation." The message concluded, "No suspect or person of interest has been identified at this time." Savannah, for her part, has been absent from the Today show amid the ongoing search. After sharing a statement on behalf of her family during the Monday, February 2, broadcast, Savannah spoke out later that day via Instagram. Savannah Guthrie's Family Confirms 'Today' Host's Mom, 84, Is Missing "We believe in prayer. We believe in voices raised in unison, in love, in hope. We believe in goodness. We believe in humanity. Above all, we believe in Him," Savannah wrote. "Thank you for lifting your prayers with ours for our beloved mom, our dearest Nancy, a woman of deep conviction, a good and faithful servant. Raise your prayers with us and believe with us that she will be lifted by them in this very moment." Savannah went on to share a Bible verse, writing, "We need you. 'He will keep in perfect peace those whose hearts are steadfast, trusting in the Lord.' A verse of Isaiah for all time for all of us." While sharing a graphic that read "Please Pray," Savannah concluded her message with a plea: "Bring her home."