A Turkish army tank drives towards to the border in Karkamis on the Turkish-Syrian border in the southeastern Gaziantep province Thomson Reuters MOSCOW (Reuters) - The Kremlin said on Wednesday that Turkish President Tayyip Erdogan's statement that his forces in Syria were there to topple President Bashar al-Assad had come as a surprise to Moscow and that it expected an explanation from Ankara.

In a speech on Tuesday, Erdogan condemned what he said was the failure of the United Nations in Syria and cast Turkey's incursion in August, when it sent tanks, fighter jets and special forces over the border, as an act of exasperation.

"We are there to bring justice. We are there to end the rule of the cruel Assad, who has been spreading state terror," Erdogan said.

"The announcement really came as news to us," Kremlin spokesman Dmitry Peskov told reporters on a conference call.

"It is a very serious statement and one which differs from previous ones and with our understanding of the situation. We hope that our Turkish partners will provide us with some kind of explanation about this."