Moscow - The European Union staunchly supports Ukraine's territorial integrity in the face of Russian aggression, European Council President Donald Tusk said Thursday during a visit to Kiev.

"We stand steadfast behind Ukraine," Tusk said in a televised press conference with Ukrainian President Petro Poroshenko and European Commission President Jean-Claude Juncker.

"You are too strong"

"We do not recognize the illegal annexation of Crimea," Tusk said, referring to the southern Ukrainian peninsula that Russia occupied three years ago, prompting outcry in the West.

"Today I can see clearly that you will not be defeated by an external enemy. You are too strong," Tusk said.

Poroshenko expressed hope that the Ukraine conflict would end by next year, saying the next EU-Ukraine summit could possibly be held in Crimea or Ukraine's war-torn eastern region of Donetsk.

Ukraine's military has been battling Russia-aligned rebels near the Russian border for the past three years. About 10,000 people have been killed in the conflict, which erupted when Ukraine ousted its pro-Russian president amid mass protests calling for closer ties with the West.

The EU has reinforced its relations with Ukraine in recent days by completing the adoption of an association agreement with the former Soviet republic.

Controversy over the agreement had catalyzed Ukraine's political crisis three years ago: It led to the ouster of then-president Viktor Yanukovych, who wanted to indefinitely postpone the deal in favour of closer ties with Russia.

"Together we have achieved a lot"

Ukraine's internal reforms also featured prominently in the EU-Ukraine summit in Kiev this week, with EU leaders praising Ukraine for its efforts against corruption.

Ukraine in the past three years has made more progress against corruption than it had in the previous two decades, said Juncker. "Ukraine should be proud of what it has achieved," Juncker said at the press conference. Corruption has been a major factor undermining Ukraine's prosperity, he added.

Tusk expressed a similar sentiment: "If you can withstand the burden of reforms and not give up, then you will reach your dreams and goals."

"Together we have achieved a lot," Tusk said, "but we are still only halfway down the road."