The EU will hold an emergency summit in Brussels late Thursday on the Russian-Ukrainian crisis, European Council President Charles Michel announced in a letter to the bloc's leaders.

"It is important that we continue to be united and determined and jointly define our collective approach and actions," he said in the letter published on Wednesday.

"Therefore, I would like to invite you for a special European Council (summit) on Thursday 24 February, which will take place in person in Brussels and start at 20:00 (19:00 GMT)."

The summit follows the EU's adoption of sanctions against Russia for declaring the independence of DPR and LPR. 

The European Union threatened Russia with more, tougher sanctions should the Russian forces “invade further”. 

"The use of force and coercion to change borders has no place in the 21st century," Michel wrote in his summit invitation.

"The aggressive actions by the Russian Federation violate international law and the territorial integrity and sovereignty of Ukraine. They also undermine the European security order," he claimed.

So they claim, although Putin said, on the use of the military in Donbass, "We will fulfill our obligations if necessary," stressing that he does not mean that Russian troops will enter Donbass right away.

This comes one day after President Putin’s speech whereby he said that all agreements on Karabakh conflict resolution are fully implemented after his talks with Aliyev, stressing that “Minsk agreements do not exist anymore, we recognized DPR and LPR."

Putin stressed that the Minsk Agreements, which were to preserve peace and stability in eastern Europe, were killed by Kiev's actions long before Moscow's recognition of the breakaway Donetsk and Luhansk people's republics.

Russian President Vladimir Putin had signed on Tuesday federal laws on cooperation and friendship between Russia and the two Donbass republics.

Following the signing ceremony, Putin added that the recognition of DPR and LPR envisions recognition of their constitutions which indicate borders of these republics.

Russia’s recent decision to recognize DPR and LPR followed a deterioration of the situation on the line of contact between Ukraine and the breakaway republics. Russia has repeatedly denied any intention of invading Ukraine, but nevertheless, the West continued to militarize Ukraine, which in its turn, bombed the DPR and LPR over the past few days causing civilian and military casualties, without Russia even moving an inch.