ANKARA (Reuters) - Turkey's defense minister said on Thursday the new U.S. administration has a more flexible approach to Syria and is not insisting on the Kurdish YPG militia being involved in the operation to drive Islamic State from its Raqqa stronghold.

U.S. support for the Syrian Democratic Forces, an alliance dominated by the YPG, has caused tensions with NATO ally Turkey, which views the Kurdish militia as an extension of militants fighting on its own soil.

"If we want the Raqqa operation to be successful, then it should be carried out with Arab forces in the region and not the YPG," Turkish Defense Minister Fikri Isik told reporters in Brussels.

"The new U.S. administration has a different approach to the issue. They are not insisting anymore that the operation should definitely be carried out with the YPG. They haven't yet made up their minds," he said in comments broadcast live.

The SDF alliance, which includes Arab and other groups in Syria's north as well as the YPG, has taken territory along the Syria-Turkey border as they push back Islamic State.

With air strikes and special ground forces from the U.S.-led coalition, the SDF is in the middle of a multi-phased operation to encircle Raqqa, Islamic State's base of operations in Syria.

A key decision for the Trump administration will be whether to provide weapons to the YPG despite Turkish objections. The U.S. says weapons provided to the SDF are so far limited to its Arab elements.

"We are working with the U.S. on the withdrawal of the YPG from Manbij by the time the al-Bab operation is completed," Isik said, referring to a town currently under SDF control.

Isik added that Turkey's priority after al-Bab would be advancing towards Manbij and Raqqa. He also said U.S. chief of staff Joseph Dunford would visit Turkey on Friday.

(Reporting by Ece Toksabay and Tuvan Gumrukcu; Writing by Daren Butler; Editing by Nick Tattersall)