Turkish President Recep Tayyip said on Wednesday that up to three million Syrian refugees could be returned to a "safe zone" it is seeking to establish in northern Syria. Turkey is home to more than 3.6 million Syrian refugees — the highest number in the world — and there have been signs of a public backlash over their presence after eight long years of war in its neighbor to the south. Working with the United States, Turkish forces are seeking to clear a swathe of northern Syria, in part to push Kurdish rebels away from its border but also to facilitate the return of refugees. If successful, "we will be able to house, depending on the depth of the safe zone, between two and three million Syrian refugees that are currently in Turkey and Europe," Erdogan said in a televised speech. Erdogan said earlier this week that he envisions the "peace corridor" as stretching right across northern Syria all the way to Deir ez-Zor and Raqqa — which he said would allow even more than three million to return. He called for "much greater support" from Europe in realizing the plan. For Turkey, a key priority is curbing the influence of Syrian Kurdish People's Protection Units (YPG), which it sees as an off-shoot of the Kurdish separatists in its own territory. On Wednesday, Erdogan repeated his threat to launch military attacks against the Kurds if they are not pushed back from the Turkish border by the end of the month. "As we've said, if we don't see results in the next two weeks, we will activate our plan," he said. But the YPG is firmly established in northern Syria and has been a crucial ally of the United States in fighting Daesh (the so-called IS), creating a tricky balancing act for Washington. Ankara says US promises to push the YPG back from the Turkish border have so far been "cosmetic". Turkey has twice launched unilateral operations into Syria against the YPG and Islamic State group, in 2016 and 2018. Meanwhile in another development, Russia on Wednesday accused the US and Syrian rebels of blocking the evacuation of a refugee camp in southern Syria, where the UN has described conditions as "critical". The Russian army called the isolated Rukban camp in a US-controlled desert near the Jordanian border a "death camp". According to Moscow, a key backer of the Syrian regime, a UN-led evacuation operation is scheduled to begin on Sept. 27 to transfer the camp's thousands of refugees to government-controlled territory. But Russian army general Mikhail Mizintsev told a press conference the evacuation was "on the verge of collapse because of provocations by rebels under US control." According to the Russian army, the rebels refused to ensure the safety of evacuation convoys and took some of the humanitarian aid distributed to the camp. Rights groups have warned that civilians returning to government-led territory have faced detention and conscription. The UN said it sent aid to the Rukban camp this month, the first such delivery since February. According to the UN, some 12,700 people remain in the camp which is near a base used by the US-led coalition. Syria and Russia said in February they had opened corridors out of the camp, calling on residents to leave. Russian President Vladimir Putin and his Turkish and Iranian counterparts met in Turkey this week for their latest summit on Syria, vowing to work together to prevent further humanitarian crises in the last rebel-held bastion of Idlib. Russian air strikes have continued in the region despite the latest ceasefire agreed by rebel-backer Ankara and Moscow on Aug. 31. — Agencies