"The latest developments have increased the need for humanitarian assistance, yet it is impossible to deliver it with the current insecurity," Robert Onus, the charity's emergency manager for Syria, said in a statement.
The group, widely known by its French initials MSF (Medecins Sans Frontieres), was operating in cities and camps including Ain Issa, Al Hol, Tal Tamer and Raqqa.
In Tal Tamer, for example, MSF said it had been distributing blankets, food and water to "thousands of people who were arriving in the town daily" since the Turkish incursion began last week.
"Given the numerous groups fighting on different sides of the conflict, we can no longer guarantee the safety of our Syrian and international staff," it said.
But while international staff will be evacuated, "we are extremely worried about the safety of our Syrian colleagues and their families who remain in northeast Syria," it said.
MSF said its personnel would remain in northwest Syria, providing health care at facilities and in mobile clinics.
Fighting in northeast Syria has been fierce and at times chaotic after Turkey launched its offensive against the Kurdish-led Syrian Democratic Forces (SDF) last week.
The SDF was at the forefront of the US-backed coalition fighting the Islamic State group, but Ankara considers the Kurdish militia which dominates the SDF a terrorist threat.
Having lost US support after President Donald Trump's sudden move last week to withdraw almost all remaining American forces in northern Syria, the Kurds have signed a deal with Syria's President Bashar Al-Assad.
The fighting has left dozens of civilians dead, mostly on the Kurdish side, and displaced at least 160,000 people.
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