MOSCOW — Under the watchful eye of Russian state television, several hundred pro-Russian demonstrators in the city of Donetsk, in eastern Ukraine, declared Monday that they were forming an independent republic and urged President Vladimir Putin to send troops to the region as a peacekeeping force, even though there are no obvious threats to peace in the area.
The actions in Donetsk and three other cities in eastern Ukraine, which included a demand for a referendum on seceding from Ukraine and joining Russia, seemed an effort by the activists to mimic some of the events that preceded Russia’s invasion and annexation of Crimea. But there were no immediate indications that the Kremlin was receptive to the pleas.
Secretary of State John Kerry told the Russian foreign minister, Sergey Lavrov, in a phone call Monday that there would be “further costs” if Russia took additional steps to destabilize Ukraine, the State Department said.
Kerry said in the call that the United States was monitoring with growing concern the pro-Russia protests in Donetsk, Kharkiv, Lugansk and Mariupol, and did not believe they were a “spontaneous set of events,” said Jen Psaki, the State Department spokeswoman.
“He noted in particular the recent arrests of Russian intelligence operatives working in Ukraine,” Psaki added.
The Obama administration has warned Russia that it is prepared to impose new sanctions if Russia intervenes militarily or covertly to undermine the new Ukrainian government, a point Kerry repeated Monday.
“He made clear that any further Russian effort to destabilize Ukraine will incur further costs for Russia,” Psaki said without providing details. The United States, Russia, Ukraine and the European Union are planning to meet jointly in the next 10 days to discuss the situation in Ukraine, Psaki said.
NATO’s top commander, Gen. Philip M. Breedlove said last week that the approximately 40,000 Russian troops near the Ukrainian border are capable of intervening in eastern Ukraine on 12 hours’ notice and could accomplish their military objectives in three to five days.
In Kiev on Monday morning, the acting prime minister, Arseniy P. Yatsenyuk, said Russia was carrying out a campaign “to destabilize the situation, a plan to ensure that foreign troops could cross the border and capture the territory of the country.” He added, “We will not allow this.”
Speaking at the start of a government meeting, Yatsenyuk said: “There is a script being written in the Russian Federation, for which there is only one purpose: the dismemberment and destruction of Ukraine and the transformation of Ukraine into the territory of slavery under the dictates of Russia.”
Russian officials, including Lavrov, have said that they have no intention of taking military action in eastern Ukraine, and in a statement Monday afternoon, the Russian Foreign Ministry reiterated its call for federalizing Ukraine, a move that would substantially weaken the government in Kiev.
“As the Russian side has noted repeatedly, it is difficult to count on a long-term stabilization of Ukraine without a real constitutional reform within the framework of which, through federalization, the interests of all regions would be ensured, its nonaligned status maintained and the special role of the Russian language reinforced,” the Foreign Ministry said.
The Foreign Ministry also denied any role in the unrest, even though the demonstrations Sunday evening in Donetsk, Kharkiv and Lugansk seemed coordinated and bore the hallmarks of similar protests last month that were organized with support from Moscow.
“Stop poking at Russia, blaming it for all the troubles of today’s Ukraine,” the ministry said. “The Ukrainian people want to hear from Kiev, a clear answer to all the questions. It’s time to listen to these legitimate demands.”
The unrest in eastern Ukraine seemed to heighten fears in Kiev and the West about possible Russian military action a little more than a month after Russian forces occupied Crimea. The Kremlin annexed Crimea after a referendum there last month.
In Germany, a spokesman for Chancellor Angela Merkel said Monday that the government was extremely concerned about the events in eastern Ukraine and called for calm.
“The latest developments in Donetsk and in Kharkiv are something which we are all very worried about in the German government,” the spokesman, Steffen Seibert, said at a news conference. “We must urgently renew our appeal to all those in positions of responsibility to help stabilize the region and avoid such escalation.”
Even as the Kremlin denied any role, government-controlled television stations in Russia gave live coverage to the events in Donetsk on Monday, including the reading of a sort of declaration of independence of the “sovereign state of the Donetsk People’s Republic” by a pro-Russian demonstrator inside the regional administration building. Protesters occupied the building Sunday.
While the demonstrators in Donetsk announced that a ballot referendum on secession from Ukraine would be held no later than May 11 , there did not appear to be the same overwhelming support for such a move as there was in Crimea last month.
The regional prosecutor, Mykola Frantovkskiy, issued a statement calling the demonstrators’ actions illegal and saying that law enforcement officials had identified the criminal “separatists” and that “all necessary measures will be taken to apprehend the violators.”
The Donetsk City Council called on the protesters to end their occupation of government buildings and engage in negotiations. “All conflicts should be resolved legally,” the council said in a statement.
Alexei Pushkov, the head of the Foreign Affairs Committee in Russia’s lower house of Parliament, told reporters in Strasbourg, France, that the events in eastern Ukraine showed that the opinions of Russian-speakers in Ukraine cannot be ignored.
“Stability will not be achieved in Ukraine without heeding the wishes of the people who live in the eastern and southern regions of Ukraine, primarily, Russian-speaking people,” Pushkov said in France, where he was attending a session the Parliamentary Assembly of the Council of Europe, according to the Interfax news service.
The events in the east unfolded just hours after a Ukrainian military officer was shot and killed in Crimea in a confrontation with Russian troops.
A spokesman for the Ukrainian Defense Ministry, Vladislav Seleznev, said the officer, Maj. Stanislav Karchevskiy, was killed in a military dormitory where he lived with his wife and two children, next to the Novofedorivka air base in western Crimea.
The death of the Ukrainian officer was a rare instance of deadly violence as Ukrainian forces continue their withdrawal from the peninsula after its annexation by Russia.
Seleznev, the Defense Ministry spokesman, said that the Ukrainian soldier had been collecting his belongings in preparation to leave Crimea when an argument broke out with Russian service members, Reuters reported Monday.
Seleznev said that the altercation involved several Ukrainian and Russian soldiers and that there were no other injuries. He said a Russian soldier armed with an automatic weapon entered the dormitory and shot Karchevskiy, who was unarmed.
Ukraine’s provisional government in Kiev has ordered its forces to withdraw from Crimea, but an unknown number of military personnel remain on the peninsula as part of the transition, in which some military equipment is being returned to mainland Ukraine.
Seleznev said that a second Ukrainian officer, Capt. Artem Yarmolenko, was detained by Russian forces for questioning and possibly taken to Sevastopol, where the Russian military has its headquarters in Crimea.
With tensions intensifying in the east, the former prime minister, Yulia V. Tymoshenko, who is running for president in elections next month, traveled to the region.
Tymoshenko said she was committed to strengthening the autonomy of Ukraine’s regions, especially by letting them control their finances but said she opposed federalization.
She also said that she did not believe most people in Donetsk supported the protesters. “I got the impression that all of this aggression lives on its own island, separate from the life of Donetsk,” she said. “It does not at all correspond with the opinions or wishes of the people in Donetsk.