Dozens of protesters gathered around a makeshift announcement system to listen to a priest holding prayers, while workers expanded the stage on the square.
Protesters remained defiant but admitted that the future of the protest movement seemed uncertain.
"You know it is hard to make any predictions but there is one thing I am sure of - that this government won't give up that easily and just say 'yes, you won and we believe in you and now you can run the country'," said one protester, Sergey Metroflotskyi.
"So I am sure it will be difficult but we need to keep fighting," he added.
Ukrainian President Viktor Yanukovych has faced nearly a month of angry protests since his abrupt decision to shelve a political and trade agreement with the European Union in favour of closer ties to Moscow.
The rallies grew larger, swelling to hundreds of thousands, after riot police violently broke up the first small protests, injuring dozens.
On Sunday, tens of thousands of protesters favoring closer ties to the EU gathered on the square. AP