The Turkish army has completed all preparations for a military operation in the east of the Euphrates River in Syria to establish a safe zone, Turkey's Defense Ministry said on Tuesday.        

"The establishment of a Safe Zone/Peace Corridor is indispensable for Syrians to have a safe life by contributing to the stability and peace of our region," the ministry said on Twitter.        

"Turkish Armed Forces will never tolerate the creation of a terror corridor at our borders. All preparations for the operation have been completed," said the ministry.   
  
Turkey has already made its decision of clearing northern Syria of "terrorists," Turkish President Recep Tayyip Erdogan said on Monday, vowing to launch a military campaign into the east of the Euphrates at any moment.    
  
He announced that U.S. troops have started withdrawing from northern Syria after he held a phone conversation with his U.S. counterpart Donald Trump late on Sunday.  

"Turkey will soon be moving forward with its long-planned operation into northern Syria," White House Press Secretary Stephanie Grisham said in a statement, noting that the U.S. would not intervene in a Turkish offensive. 

Erdogan had earlier said the operation could come at any moment "without warning."

The People's Protection Units (YPG), which controls the east of the Euphrates, was a key partner of the United States in the fight against ISIL, but Ankara considers it as a "terrorist" offshoot of the outlawed Kurdish Workers' Party (PKK) in Syria.  

Ankara says it wants a "safe zone" along northern Syria that will act as a buffer against Kurdish forces and also allow the return home of up to two million Syrian refugees. It has previously launched two cross-border offensives against ISIL in 2016 and the YPG in 2018, with the support of Syrian rebels.

Trump's move to order the withdrawal of U.S. troops from Turkey's border with Syria was seen by critics as an abandonment of Kurdish forces. But there was confusion later on Monday when Trump tweeted that he would "obliterate" Turkey's economy if it did anything he did not like.  

The White House also said Turkey would be responsible for thousands of ISIL prisoners currently held in Kurdish detention centers.  

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Trump on Tuesday insisted that the U.S. has not "abandoned the Kurds."  

"We may be in the process of leaving Syria, but in no way have we abandoned the Kurds, who are special people and wonderful fighters," Trump tweeted.  

He stressed that Washington has an important relationship with NATO member and trading partner Turkey.  

He also said that "any unforced or unnecessary fighting by Turkey" would prompt "devastating" consequences for the country's economy. 

Syria's Deputy Foreign Minister Faisal Mekdad said Tuesday that the Syrian government will defend all Syrian areas and will not accept any form of occupation by foreign forces. 
  
"We will defend all Syrian territory, and we will not accept any occupation of Syrian land," Mekdad told the pro-government Al-Watan newspaper. 

Meanwhile, a Syrian Kurdish official said on Tuesday that the Kurdish-led authorities may open talks with Damascus and Russia to fill a security vacuum in the event of a full withdrawal of U.S. forces from the Turkish border area. 

"If America vacates the area and especially the border area for certain we, as a self administration and as the Syrian Democratic Forces (SDF), will be forced to study all the available options," Badran Jia Kurd told Reuters. 

The Kurdish-led SDF has described the U.S. decision as "a stab in the back."

Iran's Foreign Ministry said in a statement on Tuesday that Tehran opposes any Turkish military operation in Syria. 

The ministry has been following "worrying news of the possibility of the Turkish military forces entering Syrian soil and believes that the occurrence of such an action will not only not end Turkey's security concerns but will lead to widespread material and human damage," the statement said. 

On this basis Iran "is against any type of possible military operation" of that kind. 

In a phone call with his Turkish counterpart Mevlut Cavusoglu, on Monday, Iran's Foreign Minister Mohammad Javad Zarif backed Syrian sovereignty and opposed Turkey's military action.  

"Zarif opposed military action and emphasized respect for Syria's territorial integrity and national sovereignty and the need to fight terrorism and bring stability and security to Syria," Iran's state broadcaster IRIB reported.

European, British and United Nations officials have also expressed concern about Turkey's threatened invasion of northeast Syria.

(With input from agencies)

(Cover: Turkish and U.S. troops return from a joint patrol in northern Syria, as it is pictured from near the Turkish town of Akcakale, September 8, 2019. /Reuters Photo)