During his meeting with journalists in Dehli, the U.S. president Barack Obama made Moscow responsible for escalation of the conflict in Ukraine and promised to increase pressure on Russia, Reuters reports.

According to him, Washington is "deeply concerned about the latest break in the ceasefire and the aggression that these separatists -- with Russian backing, Russian equipment, Russian financing, Russian training and Russian troops -- are conducting." The EU leaders are also deeply concerned about the situation. "I call therefore openly upon Russia to use its considerable influence over separatist leaders and to stop any form of military, political or financial support.

This would prevent disastrous consequences for all," said a statement by the EU's Federica Mogherini. She also announced an extraordinary meeting of the EU foreign ministers to discuss the situation in the Ukraine.

The UN Security Council holds a special meeting on Monday on the violence in eastern Ukraine after Saturday's assault on Mariupol -- the main city standing between separatist territory near the Russian border and the Black Sea peninsula of Crimea that Moscow annexed in March. A rocket barrage killed 30, including 2 children, and about 100 were injured, Ukraine president Petro Poroshenko reported at his national security council and defense meeting on Sunday.

The OSCE monitoring mission stated that the rockets came to Mariupol from north-east - the territory controlled by Donetsk people's republic.

But separatists deny having that kind of missiles. The Kremlin flatly denies arming and funding the militants, as the West alleges.

As RBC UKRAINE reported on Sunday, the National security and defence council of Ukraine instructed the government to begin the appeal procedure to the Hague Tribunal on crimes against humanity committed by terrorists against Ukrainian citizens in 2014-2015 years and recognition of "DNR" (Donetsk People's Republic) and "LNR" (Luhansk People's Republic) as terrorist organizations.

During that meeting Poroshenko has also confirmed Kiev's adherence to the ceasefire agreement reached in September in Minsk, Belarus. But Russia and pro-Russian Ukrainian separatists accuse Kiev of not following the agreement. Moscow also accuses the government in Kiev of waging war against its own citizens and discriminating against Russian speakers, who make up the majority of the populations of Donetsk and Luhansk.

Both cities are now centers of the self-proclaimed people's republics controlled by rebels.

According to the UN report on the situation in Ukraine published on 23 January 2015, there are over 920 000 internally displaced people who were forced to flee their homes but don't want or have no money to leave the country. 600,000 fled to other countries. Those who stayed have to live without heating, electricity and water. The most threatening figures are: more than 5,000 were killed and at least 10,000 wounded.