Ukrainian President Petro Poroshenko spoke to journalists at a press conference following the Minsk negotiations.

Poroshenko said that there are trust problems between Russia and Ukraine. He said that if the Russians do not fulfill the 13-point agreement reached in Minsk, the EU should tighten sanctions against Russia.

Poroshenko noted that during the 16-hour talks with Putin in Minsk, Ukraine`s NATO membership had not been discussed.

"Unfortunately,minutes after the Minsk agreement was signed, the Russian-backed separatists intensified their military attacks. They are mostly concentrated in Debaltsevo where our armed forces are protecting the front line. My position is that the fire should be stopped immediately because it takes away lives of innocent people every hour. I am impressed by the level of the EU support. As for NATO, we did not talk about it with Putin yesterday, I trust the European leaders, though I have a problem with trusting Russia. If the agreement is violated, it will be the cause of new sanctions against Russia."