"May be day or two. But that's just logistical questions," Kerry said on the sidelines of the Davos Economic Forum.
The intra-Syrian talks have so far been scheduled for January 25 in Geneva.
Syria has been in a state of civil war since 2011, with government forces fighting several opposition factions and militant groups.
In December, the UN Security Council adopted a resolution which provides for the beginning of talks between the Syrian government and opposition in January.
Earlier on Thursday, UN Special Envoy on Syria Staffan de Mistura told Sputnik that the date of the intra-Syrian talks had not been fixed, but they were likely to take place in late January.