A senior Russian official has warned that Moscow may intervene to help the Russian-speaking residents of the Donbas region in eastern Ukraine if Ukraine launches an all-out offensive against separatists there.
And separatist rebels, backed by Russia, clashed with Ukrainian forces in the eastern region of the country.
Russia is also working to mass its forces on the border with Ukraine.
“Russian forces can intervene to defend their citizens,” said Dmitry Kozak, an official in the Russian presidency.
“Everything depends on the intensification of the conflict,” he added.
He also warned that any escalation could mark the “beginning of the end” for Ukraine, and “not a bullet in the leg, but in the face.”
The United States and Germany expressed concern over the escalating tension.
Why are tensions escalating between Ukraine and Russia?
Russia is working to reinforce its forces on the Ukrainian border, but at the same time stresses that this should not be considered as a threat.
White House spokeswoman Jane Psaki said that the number of Russian forces there is the highest since 2014, when the conflict began in eastern Ukraine, and described the situation as “extremely worrying.”
In recent months, clashes between Ukrainian forces and the Moscow-backed rebels have intensified in the Donbas region.
The death toll rose this year, with the killing of another Ukrainian soldier on Thursday, to 25, and last year alone 50 Ukrainian soldiers were killed.
The rebels said that one of their fighters was killed on the same day when Ukrainian forces fired 14 mortar shells at a village on the outskirts of Donetsk city.
In another indication of the gravity of the situation, Ukrainian President Volodymyr Zelensky visited the region on Thursday to inspect “escalation sites” and “support soldiers in difficult times in the Donbas”.
German Chancellor Angela Merkel telephoned Russian President Vladimir Putin on Thursday and called on Russia to “calm tensions” by reducing its troop reinforcements.
During the same call, Putin accused Ukraine of fueling the situation in the east of the country.
What else did the Kremlin official say?
Cusack likened the current situation of separatists to the massacre of Srebrenica, a city in Bosnia and Herzegovina that witnessed the killing of 8,000 Muslims by Bosnian Serb forces in 1995.
“If, as our president says, events were organized there, similar to Srebrenica, we might have to defend them,” Kozak said.
Putin first spoke in 2019 of the possibility that the Russian-speaking population would suffer a similar massacre of Srebrenica if Ukraine regained full control of the Donbas region without guarantees.
However, there has been no news of planning to carry out such atrocities.
Kozak indicated that the rebels could maintain their strength for the time being against the Ukrainian forces due to the presence of “combat units.”
What is the background to the events?
The roots of the current conflict go back to March 2014, when Russia annexed the Ukraine region of Crimea.
This step led to a major rift with Western countries, which prompted the European Union and the United States to impose sanctions on Russia.
A month later, rebels backed by Russia in the Donbas region, which has a predominantly Russian-speaking population, captured the Donetsk and Luhansk regions.
Western countries and NATO accused Russia of sending troops across the border to Ukraine, but Russia asserts that the Russian fighters there are “volunteers.”
Ukrainian President Zelensky came to power, pledging to bring about peace, and a ceasefire agreement was signed last July, and the two parties have been fighting, since that time, accusations of violating the agreement.
It is estimated that the conflict has killed 14,000 people.