Nicola Sturgeon has promised to give parents "as much notice as possible" if she decides not to reopen schools on January 18.
She refused to rule out keeping pupils home longer as the new strain of coronavirus sweeps the country.
Speaking in the Scottish Parliament yesterday, the First Minister confirmed the Scottish Government is still assessing the next step.
She said: "We continue to assess the situation carefully, indeed on a daily basis, and will keep Parliament updated should any changes be required over the remainder of the festive period.
"As we learn more about the new variant, we also continue to review when pupils can safely return to classrooms.
"The new strain has already made a normal scheduled return impossible - but we continue to assess whether it will be possible to reopen schools as planned on 18 January. That is what we all want and, to be clear, it remains our planning assumption.
"But we will continue to put the safety of pupils, teachers and staff first. And we will ensure as much notice as possible to parents of any changes we consider necessary."
The First Minister also warned that "even tighter" restrictions cannot be ruled out for Level 4 areas, and she vowed to keep Parliament updated should "any changes be required over the remainder of the festive period".
Despite welcoming the news of the Oxford-AstraZeneca jab being approved, Ms Sturgeon warned people of the "severity of the threat" in the new coronavirus strain.
She confirmed that 42.8 per cent of positive tests analysed at the Lighthouse Laboratories were from the new strain.
Ms Sturgeon said this variant was "fast becoming the" dominant strain", adding this was a "real concern as it is thought to be significantly more transmissible".
