ANKARA - Turkey's Foreign Ministry summoned Sweden's ambassador in Ankara to a meeting to protest contacts between two Swedish ministers and members of the Syrian Democratic Forces (SDF), which Ankara considers a terrorist group, Turkish diplomatic sources said on Tuesday.

Turkey considers the SDF to be an extension of the outlawed Kurdistan Workers Party (PKK) militia, which has waged a decades-old insurgency against the Turkish state. Ankara says the Syrian Kurdish YPG, which forms the military backbone of the SDF, is an offshoot of the PKK.