Turkey's offensive will end if Kurdish fighters leave a designated border area in northeast Syria, Turkish President Recep Tayyip Erdogan said on Wednesday, but warned that no power could stop it until then.
Erdogan said the quickest solution was for fighters to drop their weapons and pull back from the area by Wednesday evening.
The operation will end when the "safe zone" is established, he said, and Turkey was not open to negotiating this.
Erdogan made the comments in Parliament amid pressure for him to call a ceasefire and halt its incursion into Syria, now into its eighth day.
He made clear Turkey would not bow to pressure and would press ahead with the military operation until Turkish troops reach a depth of some 30 or 35 kilometer inside Syria.
He also called on the world to support Turkey's battle against Kurdish groups.
The Kremlin said on Wednesday that Turkey's military operation should not damage the political process in the country and that Ankara's actions there should be proportional.
Speaking to reporters on a conference call, Kremlin spokesman Dmitry Peskov said, however, that Moscow respected Turkey's right to defend itself.
The Kremlin said it would host Erdogan for a meeting with his Russian counterpart Vladimir Putin in the coming days, to ensure the operation does not turn into an all-out war between Turkey and Syria.
Russian Foreign Minister Sergei Lavrov also said that Moscow is committed to mediating between the Syrian government and Turkey in order to ensure security in the region.
Lavrov said in remarks carried by Russian news agencies that Moscow will also continue to encourage Syria's Kurds and government to seek rapprochement after the withdrawal of US troops from the northern border area.
Russia moved quickly Tuesday to fill the void left by the US troop pullout, deploying its military to act as a buffer as Syrian government forces moved north under the deal with the Kurds, who have sought protection from the Turkish offensive.
Lavrov blamed the US and Western nations for undermining the Syrian state, thus "pushing the Kurds toward separatism and confrontation with Arab tribes."