The state news agency Sana, quoted Ayman Sousan, assistant foreign and expatriates minister, as saying that a USA presence on Syrian soil represented "utter aggression and a blatant violation of the global law".
The U.S. -led worldwide coalition against Daesh said on Sunday that it would establish a 30,000-strong new border security force with the SDF/PKK - a group largely controlled and manned by the PYD/PKK terrorist organization.
"(It's) not a bad system", he said, explaining that some early reactions to Trump's tweets have usually come in by the time he sees them. Turkey considers the Syrian YPG as an extension of the Kurdistan Workers' Party (PKK) militant group, which has fought a bloody insurgency in southeast Turkey for more than three decades.
Similarly, Iranian influence inside Syria through Tehran's use of proxy forces alongside its own military presence remains a reality that must be checked, Tillerson said.
The secretary of state said the U.S.
"The president has used it to great effect, by bypassing the way you traditionally communicate", Tillerson said.
However, he said, more clarity was needed on how Washington will force the implementation of the political process and how it "will force the Assad regime into accepting a political settlement that leads to establishing a safe and neutral environment that leads to a transition through free and fair elections". "Instead, we will encourage worldwide assistance to rebuild areas the global coalition and its local partners have liberated from Islamic State", he said.
"We can not allow history to repeat itself in Syria", he said, referring to what he described as mistakes made by the Obama administration in withdrawing USA troops prematurely from Iraq and failing to stabilize Libya after North Atlantic Treaty Organisation airstrikes that led to the ousting of the late President Moammar Gadhafi.
Tillerson said the main goals of USA stabilization efforts in Syria are to create the conditions for Syrian refugees to return to the country, to curb Iranian influence in the region and to pave the way for United Nations -supervised elections aimed at securing new leadership in Damascus. In short, this point possibly ties the USA to being in Syria until Assad is gone.
The United Nations Special Envoy for Syria said on Wednesday he had invited the Syrian government and opposition to a special meeting next week in Vienna.
"Calling for patience As a candidate, Donald Trump was critical of his predecessors" military interventions in the Middle East, but as United States president, he has had to commit to an extended presence in Afghanistan and, now, Syria.
Backed by Russian Federation and Iran, Assad has reasserted control over much of Syria.
One of the starkest illustrations of the risks of the entanglement is unfolding now, as Turkey escalates threats to attack the Kurdish enclaves of Afrin and Manbij in northern Syria.