The Turkish president has vowed to push forward with the cross-border operation against the Kurdish-run Afrin enclave in northern Syria that has raised concerns among many of Ankara's allies.
President Recep Tayyip Erdogan's comments on January 24 came after a telephone call with U.S. President Donald Trump, who urged the Turkish leader to "avoid any actions that might risk conflict between Turkish and American forces."
Trump also emphasized that the continued violence in Afrin "was undercutting our shared goals in Syria" of defeating the Islamic State (IS) militant group, White House spokeswoman Sarah Sanders said in a statement.
Turkish Prime Minister Binali Yildirim has said the operation, which involves Turkish troops accompanied by allied Syrian rebels and backed by war planes, artillery, and tanks, was aimed at creating a security zone some 30 kilometers deep inside Syria.
The operation -- dubbed "Olive Branch" -- was launched on January 20 and focuses on a Kurdish-held area close to the Turkish border.
Erdogan said Turkish-led forces would extend the mission to Manbij, a city captured from IS in 2016 by Kurdish-led forces, backed by the United States.
'Exterminate The Terrorists'
A Kurdish official told the German dpa news agency that U.S. soldiers are still in Manbij, bringing up the possibility of unintended clashes between the forces of the NATO allies.
"Starting with Manbij, we will destroy this game along our borders and completely cleanse our region of this mischief," Erdogan said, vowing to "exterminate the terrorists."
The Syrian government has condemned what it called "Turkish aggression on Afrin."
Russian President Vladimir Putin’s spokesman Dmitry Peskov has said that Moscow is "carefully watching the operation" in Afrin" and is in touch with both the Turkish and Syrian governments.
Russia has given President Bashar al-Assad's government crucial support throughout the Syria war, which has killed hundreds of thousands of people since it began with a crackdown on protests in 2011.
On January 22, Russian Foreign Minister Sergei Lavrov accused Washington of "actively" encouraging separatist sentiment among Syrian Kurds and of "discouraging the Kurds from dialogue" with the Syrian government.
"This is either a lack of understanding of the situation or an absolutely conscious provocation," Lavrov told reporters in Moscow.
During a visit to London, U.S. Secretary of State Rex Tillerson said that the United States is "concerned about the Turkish incident" in northern Syria and called on both sides to show restraint, according to a pool report supplied to the Reuters news agency.
"We recognize and fully appreciate Turkey's legitimate right to protect its own citizens from terrorist elements," he said, adding that Washington is aiming to "see what we can do to work together to address Turkey’s legitimate security concerns."
A NATO statement said Turkey has suffered from terrorism and has the right to self-defense but urged Ankara to do so in a "proportionate and measured way," the Associated Press reported.