Ukraine's position in negotiations with Russia is getting tougher, Ukrainian Foreign Minister Dmitry Kuleba said in an interview with German newspaper Welt published on Monday.

"Now we feel more confident in the fight, so our position in the negotiations is also getting tougher," Kuleba said, adding that the real problem now is that Russia does not want to take part in real and substantive negotiations.

The Russian side has yet to respond to the claim.