Speaking at the 50th Munich Security Conference on Saturday, Ban warned the warring sides not to use stall tactics at the talks as a way to continue fighting in Syria.
Ban said he called on US Secretary of State John Kerry and Russian Foreign Minister Sergey Lavrov to pressure the two sides into ensuring their attendance at the second round of talks.
"The parties may be still fighting but they are also talking," Ban said. "This is the only hope for a political solution."
No progress was made on any key matters during the first round of Geneva II talks.
The Syrian opposition has announced its intention to attend the second round of talks. The delegation of the Syrian government has said it must consult with Damascus before deciding.