BELGRADE, April 7. /TASS/. The conflict in Ukraine has turned into "difficult trench warfare," Serbian President Aleksandar Vucic said in an interview to the RTS television aired late on Thursday.

"Judging by how the situation unfolds, none of the sides can win," he said, adding that the crisis "has turned into difficult trench warfare."

Earlier, Vucic said he was "afraid" of the current global sitaution.

Vucic said in February the conflict in Ukraine would only worsen and widen in the next five or six months to ultimately become uncontrollable. He anticipated that the decision to send tanks to Ukraine would be followed by a decision to supply Kiev with F-16 fighter jets.