Several thousand people filed through Independence Square, still full of barricades and memorials to more than 80 people killed last month by snipers.
And the government announced plans to recruit 10,000 people within the next 15 days for its new National Guard.
"People will have the opportunity to defend the country," interim Prime Minister Arseniy Yatsenyuk told a cabinet meeting.
He also promised that "separatist ringleaders" who were trying to destroy Ukrainian independence would be held to account.
"We will find all of themâ€¦ and bring them to justice and try them in Ukrainian and international courts," he said.
"The ground will burn beneath their feet."
Wording of ballot paper
Law and order breakdown
Is Russian intervention legal?
But the truth is that there is little that the authorities here can do without significant outside help. Just as they are watching closely for the next move from Moscow, so they are expecting action from their Western allies.
And the drumbeat of diplomacy has certainly not faded.
Both the United States and the European Union have made it clear again that the referendum in Crimea is "illegal and illegitimate and its outcome will not be recognised."
When EU foreign ministers meet in Brussels on Monday, they are expected to extend sanctions against Russia - including asset freezes and travel bans against named individuals.
UK Foreign Secretary William Hague said Russia must now face "economic and political consequences".
But there are still different opinions within Europe about how wide-ranging the list of names should be.
One possibility is that an announcement in Brussels on Monday will focus on officials in Crimea itself, with the threat of imposing similar measures against senior figures in Moscow held in reserve.
Many Western diplomats are waiting to see exactly how Russia will respond to the result of the referendum. The Russian parliament is due to consider the proposal for Crimea to rejoin Russia on 21 March.
But for anyone looking for compromise, the signs aren't good. President Vladimir Putin told the German Chancellor Angela Merkel on Sunday that Russia would respect the choice of the residents of Crimea.
And he expressed concern about the escalation of tension in eastern Ukraine by "radical groups with the connivance of the authorities in Kiev".
US Secretary of State John Kerry spoke by phone with his Russian counterpart, Sergei Lavrov, as voting in Crimea was under way.
A senior State Department official said Mr Kerry told Mr Lavrov that the crisis in Crimea could only be resolved politically, through reform of the Ukrainian constitution.
But while Western officials have not given up on diplomacy, there are few illusions about Moscow's position.
And if President Putin chose to move Russian forces into parts of eastern Ukraine, under whatever pretext, this crisis would move into a new and far more dangerous phase.
For now, the government in Kiev can only watch and wait, and hope that Western promises of massive financial assistance materialise soon.
There is a feeling here that as well as threatening Ukraine's security and territorial integrity, Russia wants to undermine the viability of the new government, and bring this country close to collapse.
The real issue for Moscow may not be Crimea. It may be the long-term example that a westward-leaning democratic Ukraine could set in Russia itself.
As voters cast their ballots in Crimea, the mood in Kiev was downbeat: anxiety, mixed with defiance.