The Vatican spokesman, Greg Burke, and his deputy resigned suddenly Monday amid an overhaul of the Vatican's communications operations that coincides with a troubled period in Pope Francis' papacy.

In a tweet, Burke said he and his deputy, Paloma Garcia Ovejero, had resigned effective Jan. 1. Francis accepted the resignation Monday, the Vatican said in a statement.

"At this time of transition in Vatican communications, we think it's best the Holy Father is completely free to assemble a new team," Burke wrote.

He and Garcia both thanked the pope. "A stage is ending. Thank you for these two and a half years," Garcia tweeted.

Francis named a longtime member of the Vatican's communications operations, Alessandro Gisotti, as an interim replacement.

The pope has recently overhauled the Vatican's media operations for the second time by ousting the longtime editor of the Vatican newspaper L'Osservatore Romano and naming a new director of editorial content for all Vatican media, the Italian journalist Andrea Tornielli.

The resignations clearly took the new team by surprise.

The head of Vatican communications, Paolo Ruffini, said he had learned of the decision by Burke and Garcia and respected it. He praised their professionalism and said he had full confidence in Gisotti, who had been a longtime journalist with Vatican Radio and more recently had been head of social media for the Vatican.

"The year ahead is full of important appointments that will require maximum communications efforts," Ruffini said in a statement.

It was perhaps a reference to Francis' high-stakes summit on preventing clergy sex abuse in February, as well as his multiple foreign trips planned for 2019: Panama, United Arab Emirates, Morocco, Bulgaria and Macedonia in the first half of the year, and rumored trips to Madagascar and Japan in the second half.

Francis also has to deal with continued fallout from the clergy abuse scandal, in Chile, the U.S. and beyond. The next year will likely see the outcome of a canonical investigation into ex-Cardinal Theodore McCarrick, accused of sexually abusing minors and adult seminarians, as well as the results of a Vatican investigation into McCarrick's rise through church ranks.

Burke, then a Fox TV correspondent in Rome, was hired as a communications adviser for the Vatican's secretariat of state in 2012. At the time, the papacy of Pope Benedict XVI had suffered a series of communications blunders, and it was thought that Burke could provide guidance.

In 2015, Burke was named deputy spokesman under the Rev. Federico Lombardi, an Italian Jesuit.

When Lombardi retired in 2016, Burke became main spokesman and was joined by Garcia, the first woman to ever hold the position of deputy. Garcia had been the Vatican correspondent for the Cadena Cope, the Spanish broadcaster.