The 60-year-old Irish actor, whose adopted daughter Charlotte, 41, died last Friday after a three-year battle with ovarian cancer, the same disease that killed her mother Cassandra and grandmother, is throwing himself into his work despite being "devastated" and jetted from London back to Belgrade, Serbia, to resume filming his new movie 'November Man' on Tuesday.
A source close to the 'I Don't Know How She Does It' star told UsMagazine.com: "Pierce is beside himself, having to deal with this kind of loss again."
The actor is also trying to comfort Charlotte's husband Alex Smith, daughter Isabella, 14, and son Lucas, eight.
The insider said: "He's trying to be what comfort he can to her family, having been through it before himself. He will certainly push forward and pray that this brings more awareness to the tragedy cancer is."
The family "had so much hope" that Charlotte would recover from the illness, according to the family friend, who added: "There were moments of true hope where they thought [the cancer] had been beaten, that's what makes it so difficult."
Pierce adopted Charlotte and her brother Christopher, the children of Pierce's first wife Cassandra following the death of their father Dermot Harris in 1986.
He and Cassandra went on to have a son Sean in 1983 before her death in late 1991.
Pierce has been married to Keely Shaye Smith since 2001 and the couple have two children, Dylan, 16 and Paris, 12.
Meanwhile a mass is set to be planned in honor of Brosnan's late daughter in California.
Staff at the 60-year-old actor's local church in Malibu, California, have paid tribute to the star's adopted daughter Charlotte and say they will put on a special service in her memory.
Sister Mary Prendergast, of Our Lady of Malibu Church, explained: “We are very sad to hear about Mr. Brosnan’s daughter passing and he is in all our thoughts and prayers.
“Mr. Brosnan has attended the church for some years and his children have attended our school. Today we will put Charlotte’s name in the prayer book and when he returns to America we will be here to offer him support and be able to plan a mass in Charlotte’s honour, should
he desire us to do so.”