WASHINGTON (REUTERS) - The US Senate on Monday (Oct 16) voted to confirm President Donald Trump's nomination of Callista Gingrich to be the US Ambassador to the Vatican.

Gingrich, 51, an author, documentary filmmaker and former congressional aide, is the wife of former Speaker of the US House of Representatives Newt Gingrich, a vocal Trump ally.

Her nomination was approved on a 70-23 vote.

Gingrich's nomination to the post at the Holy See in May caused some controversy because of her marriage to Gingrich, with whom she became involved when he was still married to his second wife. Gingrich is Roman Catholic.

Gingrich may need to smooth over relations with Pope Francis, who has criticised the Trump administration's positions on the environment and immigration.