In an interview published Sunday, a member of the royal family provided a significant update on King Charles III’s cancer battle, and said that he’s eager to resume his official duties. The news comes from Peter Phillips, the son of Princess Anne and ex-husband Captain Mark Phillips.

Phillips spoke with Sky News Australia shortly before Catherine, Princess of Wales announced that she had also been diagnosed with cancer, the news agency says. The full conversation with the king’s nephew was broadcast on Australian television on Sunday.

Phillips, the first grandchild of Queen Elizabeth II and Prince Phillip, was fifth in line for the crown prior to the birth of his cousins and their kids. (He’s now 18th in the line of succession.) “He’s in good spirits,” Phillips says of his uncle, who announced in February that he was undergoing treatments for an unspecified form of cancer.

The king’s good mood is sometimes tempered by his desire to return to public life, Phillips says. “He is very pragmatic (and) he understands that there’s a period of time that he really needs to focus on himself,” Phillips says of Charles. “I think, ultimately, he’s hugely frustrated. He’s frustrated that he can’t get on and do everything that he wants to be able to do.”

This isn’t the first time Charles’s demeanor has been characterized as both “pragmatic” and “frustrated.” Sources close to the king shared that same sentiment with Vanity Fair last month, saying then that “The king is both pragmatic and optimistic,” but is also “frustrated” by his diagnosis.

According to Phillips, Charles “is always pushing his staff and everybody and his doctors and nurses to be able to say ‘actually come on, you know, can I do this? Can I do that?’”

“So the overriding message would be that he’s obviously very keen to get back to a form of normality,” Phillips says.