A controversial new 1,000-room palace built for Turkish President Recep Tayyip Erdogan will cost about $615mln - nearly twice the previous estimate, Turkish officials say, according to BBC News.

Known as Ak Saray (White Palace), it was built on a forested hilltop on the edge of the capital Ankara, on more than 150,000 sq m of land.

Erdogan opened the palace on Aug 30 after becoming president.

His AK Party has dominated Turkish politics for more than a decade.

The palace is bigger than the White House in Washington, the Kremlin in Moscow and even the Palace of Versailles near Paris.

Finance Minister Mehmet Simsek, quoted by Turkey's Hurriyet newspaper, said most of the 1.37bn Turkish lira ($615mln) cost had been paid, but another $135mln had been budgeted for it in 2015.

The palace has sumptuous marble corridors and atriums, as well as high-tech systems to prevent electronic eavesdropping.

Environmentalists accuse Erdogan of spending public money on lavish construction projects to the detriment of green areas. Activists defending Istanbul's iconic Gezi Park clashed with police in June 2013.

Hurriyet says the palace project was controversial because hundreds of trees were cut down to make space for it, in what had been a forest reserve bequeathed to the nation by modern Turkey's founding father, Mustafa Kemal Ataturk.

The finance minister also said $185m would be spent on a new Airbus A330-200 presidential jet.

A presidential aide, Fahri Kasirga, said other presidential properties would be renovated next year, notably the Huber Palace in Istanbul and a guest house in Marmaris, on the Aegean coast.

Erdogan has moved out of the more modest Cankaya Palace in Ankara, which will now be used by Prime Minister Ahmet Davutoglu.