Prime Minister Malcolm Turnbull says he and his wife Lucy are acutely aware of the hurt Barnaby Joyce's marriage breakdown has caused his estranged wife and daughters.

Mr Turnbull would not be drawn on reports the Deputy Prime Minister's new partner and former staffer was offered a posting in a colleague's office last year, saying he did not want to publicly discuss private matters.

"It is a tough and distressing episode and I am very conscious - Lucy and I are very conscious - of the hurt occasioned to Natalie and their daughters in particular," he told reporters in Canberra on Friday.

"So that's why I don't want to add or contribute to the discussion about it."