"There is no doubt that the security sector of Ukraine reformed in keeping with NATO standards will become an important factor not only for our country's national security, but also for the reinforcement of European security and European stability," he said.

Poroshenko also said that the Ukrainian army is among the strongest armed forces on the continent.

"It is even unpleasant to think now which army Ukraine had a little more than a year ago. Today, the Ukrainian armed forces, after the reform, after beefing up and gaining combat experience, are among the strongest ones on the continent," he said.

In his words, the main goal now is to make the army more efficient and combat-capable, because the "threat of Russian invasion, the threat of further aggression does not disappear, and we'll unfortunately have to live with this for many years," Poroshenko said.