US President Donald Trump threatened on Monday Turkey with economic devastation if it attacks Syrian Kurdish fighters allied with Washington. “Will attack again from existing nearby base if it reforms. Will devastate Turkey economically if they hit Kurds. Create 20 mile safe zone...Likewise, do not want the Kurds to provoke Turkey,” Trump wrote on Twitter. Relations between the two NATO allies have been strained over US backing for the Kurdish People’s Protection Units (YPG), which Turkey views as an extension of the outlawed Kurdistan Workers Party (PKK) that is waging a decades-long insurgency on Turkish soil. The lira slid as much as 1.6 percent to 5.5450 against the dollar in wake of Trump’s threats. Turkish presidential spokesman Ibrahim Kalin said Trump should respect Washington’s alliance with Ankara. “Mr @realDonaldTrump It is a fatal mistake to equate Syrian Kurds with the PKK, which is on the US terrorists list, and its Syria branch PYD/YPG,” spokesman Ibrahim Kalin wrote on Twitter. “Terrorists can’t be your partners & allies. Turkey expects the US to honor our strategic partnership and doesn’t want it to be shadowed by terrorist propaganda,” he said on Monday. Trump gave no details about the safe zone proposal. Secretary of State Mike Pompeo said on Monday that Trump’s threat against Ankara would not change plans to withdraw troops from Syria. Speaking from Riyadh, he added that the US message on the Kurds has been straightforward and unchanged since Trump made the decision to withdraw the troops last month. "The administration has been very consistent with respect to our requirement that the Turks not go after the Kurds in ways that are inappropriate," Pompeo said. "If they are terrorists, were all about taking down extremists wherever we find them. I think the presidents comments this morning are consistent with that." Asked specifically about what Trump meant by devastating Turkeys economy, Pompeo replied: "We apply sanctions in many places around the world. I assume hes speaking about those kinds of things but you would have to ask him." Trump declared US forces had succeeded in their mission to defeat the ISIS group and were no longer needed in Syria. However, US officials have given mixed messages since then. The US-led coalition said on Friday it had started the pullout but officials said later it involved only equipment, not troops. Turkish Foreign Minister Mevlut Cavusoglu said Ankara was not against the idea of a “secure zone” along the border, but added that strategic partners and allies should not communicate over social media. “Nothing can be achieved by threatening Turkey economically. We need to look at how we can coordinate together and how we can solve this,” he said in a news conference with Luxembourg’s foreign minister. The YPG has been a US ally in the fight against ISIS and it controls swaths of northern Syria. Erdogan has vowed to crush it in the wake of Trump’s decision to pull US troops out of the region. Erdogan’s communications director Fahrettin Altun said: “Turkey will continue its anti-terror fight decisively” and that it was a protector of the Kurds, not their enemy. “Terror is terror and it must be eradicated at its source. This is exactly what Turkey is doing in Syria,” he wrote on Twitter. Turkey has swept YPG fighters from Syria’s Afrin region and other areas west of the Euphrates river in military campaigns over the past two years. It is now threatening to strike east of the river, which it has avoided until now - partly to avoid direct confrontation with US forces. An official from the US-backed Syrian Democratic Forces, a coalition of militias led by the YPG, said on Sunday ISIS terrorists were “living their final moments” in the last enclave they hold near the Iraqi border.