The unrest in the restive east, which shares a border with Russia, is spiraling so fast, it has left diplomacy writhing in the dust.
In the southeastern city of Mariupol, a gang of 300 attacked a Ukrainian military base Thursday, leading to gunfire between the two sides.
In Donetsk, the self-declared chairman of the people's council said he wants a referendum by May 11 to ask residents if they wanted sovereignty.
And in Slaviansk, pro-Russian militants are firmly in control.
Amid it all, the U.S. is talking fresh sanctions, which will certainly not make the mood in Russia more conciliatory.
Such are the challenges the European Union and the United States confronted when bringing together the Kremlin and Kiev on Thursday to find a way out of the worst East-West crisis since the end of the Cold War.
Kiev's embattled new leaders are struggling to reassert their authority in eastern towns largely controlled by armed pro-Russian separatists.
They have tried dialogue and a show of force, both to little effect.
The Geneva gathering will be the first meeting since the crisis worsened.
Speaking in a televised question-and-answer session, Russian President Vladimir Putin said the talks were important "to figure out how to get out of this situation."
However, he also reiterated his thoughts about Kiev's new interim government -- in place since pro-Moscow President Viktor Yanukovych was ousted in February after months of protests -- calling it "illegitimate" and without a national mandate.
Presidential elections in May are taking place under "unacceptable conditions," he added.
"If the elections are to be legitimate, the constitution of Ukraine needs to be revised," he said.
Attack on military base
Earlier Thursday, in bloodshed likely to overshadow the meeting, about 300 pro-Russian militants repeatedly attacked a military base in Mariupol, Kiev said.
Soldiers opened fire, killing three attackers, wounding 13 and detaining 63 others.
But some soldiers surrendered.
"The 25th Airborne Brigade whose soldiers showed cowardice and laid down weapons will be disbanded," acting President Oleksandr Turchynov told parliament.
"Guilty soldiers will stand before the court."
Seeking another referendum In an ominous echo to what happened in Crimea just weeks ago, the Donetsk People's Republic wants to follow that region's lead and hold a referendum early next month, said Denis Pushilin, the self-declared chairman of the people's council.
The referendum will essentially ask residents which country they want to be a part of: Russia or Ukraine.
Moscow annexed the Crimean Peninsula last month after its predominantly Russian-speaking residents voted yes in a referendum.
The moved was deemed illegal by Kiev and the West, but Putin has repeatedly defended it.
"The threats to Russian-speaking people were absolutely clear, and that is why people of Crimea voted for their future and asked Russia for help," he said.
"Russia never planned any annexation, never, quite the contrary."
Putin also said Russian forces had been active in Crimea in order to support local defense forces, the first time he has acknowledged the deployment of Russian troops on the Black Sea peninsula.
Threats of sanctions Kiev and the West don't believe Putin.
They accuse Moscow of stirring up the unrest, pointing to the 40,000 Russian troops that NATO says are assembled near the Ukrainian frontier.
Moscow insists the troops are merely conducting exercises.
There are no Russian divisions in eastern Ukraine, Putin reiterated Thursday, adding that all evidence pointed to the groups causing the unrest being local residents.
He said the presence of tanks and planes constituted "a very serious crime" that authorities in Kiev were committing.
Moscow has warned in the past week that Ukraine was "on the brink of a civil war."
On Wednesday, U.S. President Barack Obama said Russia's actions risk more sanctions for the country.
"What I've said consistently is that each time Russia takes these kinds of steps that are designed to destabilize Ukraine and violate their sovereignty, that there are going to be consequences. And what you've already seen is the Russian economy weaker, capital fleeing out of Russia," Obama told CBS.
It is likely that Defense Secretary Chuck Hagel will announce additional nonlethal aid for Ukraine on Thursday, a senior Pentagon official told CNN.
The Pentagon is still not supporting lethal aid for Ukraine "because it could exacerbate the situation, which is what we do not want to do," the official said.
"If we provide arms and ammunition, then we are in the fight. We don't want that."
Since Yanukovych's ouster, Kiev's interim government has faced a wave of protests in the Russian-speaking east.
Pro-Moscow protesters took over government buildings in several cities.
And when Ukraine's armored vehicles rolled Wednesday, its attempt to take back eastern towns from pro-Russian militants seemed to stall.
In Donetsk, six armored vehicles sent into the nearby city of Kramatorsk in the morning later showed up carrying Russian flags in Slaviansk.
Russian Ambassador to the EU Vladimir Chizhov told CNN's Christiane Amanpour those Ukrainian soldiers "preferred to switch sides and join the people."
Ukraine's Defense Ministry said the vehicles had been seized by militants.
In the cities of east Ukraine, the atmosphere seemed more relaxed than it was a few days ago, with many residents apparently welcoming the presence of pro-Russian forces and their seized military vehicles.
At the same time, on the road toward Slaviansk, CNN's Phil Black encountered a heavily fortified and well-organized police checkpoint and saw signs of a large military buildup.
Attack helicopters passed overhead while armored vehicles and troop carriers rumbled by.
But despite the heightened military activity, there has so far been no effort to move into the town itself.
Pro-Russian protesters were digging in and consolidating their power.
Separately, in a reply to a letter from Putin in which he warned of gas supply disruption, the European Union said it was willing to hold talks with Russia and Ukraine on gas security.
"We believe that this approach allows for the most useful process with the Russian Federation and other third parties," European Commission President Jose Manuel Barroso said in his reply, released by the commission.
Russia supplies 30% of Europe's gas needs.
It has threatened to cut off supplies to Ukraine because of debts.
Source: CNN World