Brad Pitt is hoping for the best when it comes to getting to spend more time with his children with his estranged ex, Angelina Jolie.
A source tells ET that the 52-year-old actor is still unsure if he'll get to see his kids -- 15-year-old Maddox, 13-year-old Pax, 11-year-old Zahara, 10-year-old Shiloh, and 8-year-old twins Knox and Vivienne -- for Christmas. However, he remains "hopeful."
"Whether [Brad] sees the kids or not is still an open question, but he's obviously hopeful that he will," the source says.
WATCH: How Brad Pitt and Angelina Jolie Hit a Standstill in Custody Agreement
Earlier this month, court documents obtained by ET revealed that Pitt and 41-year-old Jolie have been unable to agree on a custody schedule. In November, Pitt's attorney, Lance Spiegel, requested for Pitt to have more time with the children than what was in their Oct. 26 temporary custody agreement, requesting the frequency of their therapy sessions to be increased to twice a week. However, Jolie's attorney, Laura Wasser, said that she defers to the therapists in order to determine the frequency of Pitt's visits, and stressed that the two should stick to their Oct. 26 agreement.
According to the documents, Spiegel then made repeated requests for Pitt to see his children, stating that Pitt had "complied with every aspect of the therapy process" and had gone through a significant amount of time not seeing or being in contact with his children.
But earlier this month, Jolie and Wasser formally filed their custody agreement, which a judge approved. The agreement grants Jolie physical custody of all six children.
"Brad was attempting to set up his own schedule with the children," a source told ET earlier this month, when Pitt's request for an emergency hearing to seal all documents related to his custody case with Jolie was denied. "He was not relying on the advice of the healthcare professionals [as to] what should be done. In order to keep everything in line with the custody agreement it had to be reinforced in court. Therefore, that forced Angelina's side to file it within the courts."
WATCH: Source Close to Angelina Jolie's Team Slams Brad Pitt Over Emergency Request to Seal Custody Docs -- 'It's a PR Scam'
Last month, Pitt spent Thanksgiving without the kids in Turks and Caicos. A source told ET that reports of Jolie inviting Pitt to Thanksgiving in Los Angeles were "not true."
"They were never planning to see Brad on Thanksgiving per the schedule created by the children and the family therapist," the source said.