Turkey is poised to launch a major offensive in Syria despite the U.S. President's warning that it will 'obliterate' the country's economy if the intervention goes too far.
The Turkish action comes after Donald Trump's decision to pull American troops from the border between Turkey and Kurdish-held north-eastern Syria.
Turkey is now reportedly expected to move into these areas, raising the prospect of clashes with US-backed Kurdish forces.
The Turkish Defence Ministry said establishment of a safe zone is essential to contribute to stability and peace of the region and for Syrians.
However, Trump threatened to "totally destroy and obliterate" Turkey's economy if it took action in Syria that he considered "off-limits".
The U.S. President threatened to destroy its economy if Ankara takes a planned military strike in Syria too far.
The threat comes even though the U.S. leader himself has opened the door for a Turkish incursion.
The withdrawal of American troops will leave Kurdish-led forces in Syria vulnerable to Turkish operations.
Ankara has long viewed the Kurdish forces as terrorists.
All preparations for a possible military operation into northeastern Syria are completed, the Turkish Defence Ministry said in a Twitter post late on Monday.
Trump's stern words seemed to be aimed at placating critics who accused him of abandoning the Syrian Kurds by pulling out U.S. forces.
Leaders from both parties and both houses of Congress joined in the criticism, including Senate Majority Leader Mitch McConnell, Trump's fellow Republican.
"As I have stated strongly before, and just to reiterate, if Turkey does anything that I, in my great and unmatched wisdom, consider to be off limits, I will totally destroy and obliterate the Economy of Turkey (I've done before!)" Trump tweeted.
Turkey's lira slid more than 2 per cent to its lowest level in more than a month against the dollar on Monday over concerns about the planned incursion into northern Syria and Trump's warning.
Investors have been closely watching tense ties between Ankara and Washington in recent months, with the countries at odds over a range of issues, including Syria and Turkey's purchase of Russian missile defence systems.
Turkey has repeatedly threatened to carry out an incursion against U.S.-backed Kurdish fighters in northeastern Syria who have links to Kurdish guerrillas operating next door in Turkey.
The United States began pulling troops back from the northeast Syrian border on Monday, effectively giving Turkey a green light to move into the area.
Earlier on Monday, Trump said the United States should leave others from European allies to Iranian foes, "to figure the situation out" in the region.
He wrote on Twitter that "it is time for us to get out of these ridiculous Endless Wars, many of them tribal, and bring our soldiers home.
"WE WILL FIGHT WHERE IT IS TO OUR BENEFIT, AND ONLY FIGHT TO WIN.
"Turkey, Europe, Syria, Iran, Iraq, Russia and the Kurds will now have to figure the situation out."
