Censor.NET reports citing Bloomberg.
Gulf states, meanwhile, said they'd send ground troops into Syria, where military gains led to the breakoff of already troubled peace talks between the government and rebels.
"It's important to see the horizon. What's going on in Syria can only go on for so long. At some point it has to change," he told journalists on the return flight from a tour of Latin America.
Asked if Turkey could manage some sudden development in Syria, Erdogan said: "Right now our security forces are prepared for all possibilities."
Opposition forces supported by Turkey and Saudi Arabia are losing more ground to the troops of Syrian President Bashar al-Assad, who is backed by Hezbollah militants and Russian airstrikes. Turkey has repeatedly urged the U.S.-led coalition fighting Islamic State militants in Syria and Iraq to increase its support for moderate rebel groups seeking the ouster of Assad.
The United Nations last week suspended its long-awaited peace conference in Geneva until later this month, after Syrian forces launched a major offensive against rebels, edging closer to retake the city of Aleppo. The talks came after four months of Russian air strikes helped to reverse the tide of the war in favor of Assad's military.
"What are you doing in Syria? You're essentially an occupier," Erdogan said, addressing Russian President Vladimir Putin, the daily reported.
Erdogan also criticized the U.S. for backing Syrian Kurdish fighters that Turkey classifies as terrorists.
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