 During summer of 2019, the Turkish president announced that Turkey could "no longer wait" and would not tolerate continued SDF presence on the Turkish-Syrian border.He stated that if the US did not agree to a deal that would remove the SDF from those areas, Turkey would unilaterally launch a full-scale invasion against SDF-held territories east of the Euphrates river, establishing a Turkish-occupied "security zone" along the border - something that US leadership viewed as "unacceptable".With the Turkish army massing along the border, the Trump Administration decided to enter into negotiations with Turkey over establishing a "safe zone", which would fundamentally address the SDF presence in Northern Syria.