The Turkish president, Recep Tayyip Erdoğan, and his Russian counterpart, Vladimir Putin, have agreed on the parameters of a proposed Turkish “safe zone” in Syria, a development that could bring an end to Ankara’s offensive against Kurdish forces over the border by severely curtailing their control of the area, The Guardian reports.

The two leaders were locked in marathon talks for more than six hours in the Russian Black Sea city of Sochi, emerging just two hours before a five-day ceasefire brokered by the US expired at 10pm local time.

Erdoğan hailed the deal as “a historic agreement” while addressing reporters alongside Putin.

“According to this agreement, Turkey and Russia will not allow any separatist agenda on Syrian territory,” he said.

Tuesday’s developments more concretely define the size and scope of the area that Turkish soldiers will occupy, adding to pockets of northern Syria that Turkey seized from Islamic State and Kurdish fighters in operations in 2016 and 2018.

The deal was widely perceived as good news for Ankara and a poor result for the Kurdish-led Syrian Democratic Forces (SDF), building as it does on the US’ agreement last week that Turkey has a right to a buffer zone on its border at their expense. Most of all, it cements Moscow’s new role as prime powerbroker in the Middle East as US influence in the region wanes.

Turkish troops in areas of north-east Syria seized since the start of the 9 October offensive will remain in situ, and Russian troops and the Syrian army will control the rest of the frontier, effectively fulfilling the goal of Turkey’s Operation Peace Spring at Russia’s discretion: the dilution of Kurdish control over the 270-mile (440km) border corridor.