Fighting is almost a daily occurrence in eastern Ukraine. That’s despite a ceasefire laid down in the Minsk Agreement between Ukraine and pro-Russian separatists. On paper, the agreement foresees the Russian-speaking Donetsk and Luhansk regions slowly gaining more autonomy before being re-integrated back into Ukraine - and ultimately an end to the fighting in the east of the country.

But the continued exchange of fire keeps Ukraine in a volatile position. The Organization for Security and Co-operation in Europe (OSCE) keeps track of ceasefire violations.

Is Ukraine complying with the OSCE?

In an exclusive interview with DW, Ukrainian President Petro Poroshenko defended the implementation of the Minsk Agreement, saying Kyiv has been fully cooperating with the OSCE.

"Ukraine is a very responsible state and a very responsible part of the Minsk Agreement. We do everything we promise. We are fully implementing the Minsk Agreement, including the withdrawal of heavy artillery and weapons."

But the OSCE has reported violations on both sides. OSCE observers recently sighted rocket launchers in government-controlled area in violation of the agreement, saying it observed "a significant increase in explosions and gunfire in the Russian-speaking Donetsk and Luhansk regions."

Crimea: lost forever?

When DW asked about his long term view on recovering Crimea, President Poroshenko didn't mince words. He said there is no excuse for Russia's annexation of Crimea last year and compared it to the Nazi takeover of Austria in 1938.

"The situation in Crimea is a complete 'Anschluss,' is an annexation of sovereign Ukrainian territory, is a brutal violation of international law. At the end of the day, international law and order should be restored," he said, adding that aggressors should be punished and that the people of Crimea want to be Ukrainian.

Poroshenko also refused to accept the notion that Crimea may be lost forever. The Ukrainian peninsula was seized by Russia a month after the February 2014 ouster of Moscow-backed President Viktor Yanukovych: "If we accept and recognize it that means that it would be the complete violation and ruin of the global security system," Poroshenko said.

Will Ukraine become a NATO member?

The Ukrainian president said he's optimistic about the European Union's solidarity with Ukraine and that he believes Kyiv will eventually join NATO, despite recent skepticism from European leaders, including German Foreign Minister Frank-Walter Steinmeier, and Russia's objections to Ukrainian membership.

"Our position is to reform the country. We need at least six or seven years to meet the criteria. The world would be more secure if Ukraine had an opportunity to do that," Poroshenko said.

"Let's not underestimate the European Union. You know what united Europe? Values. And that's why I am absolutely sure about the unity of the European Union and its solidarity with Ukraine."

Watch the full Conflict Zone interview with Tim Sebastian.