Ukrainian President Petro Poroshenko has thanked the administration of U.S. President Donald Trump for not recognizing the Kremlin's attempt to annex the Ukrainian Crimea and urged Ukraine's partners to support the "Crimea Declaration."

"I welcome Washington's historic statement on the non-recognition of an attempt by the Russian aggressor to annex the Ukrainian Crimea. It is a decent response to the Kremlin's hybrid provocations after the Helsinki meeting. I am sincerely grateful to the Presidential Administration of Donald J. Trump for the uncompromising position to support the territorial integrity of Ukraine within its internationally recognized borders," Poroshenko wrote on his Facebook page on Wednesday evening.

He said that this statement by U.S. Secretary of State Mike Pompeo "will finally deprive Kremlin of its imperial illusions."

"Regardless of the passage of time, armed occupation and illegal annexation of a part of a sovereign state will only end in one way - with the liberation of the occupied territory, restoration of territorial integrity and compensation for all damage caused by the aggressor," the report says.

Poroshenko noted that a common strategy is to move from the policy of non-recognition to the de-occupation policy.

"With one voice we will make Russia stop its aggression and respect the international law!" he said.

The document titled "Crimea Declaration" signed by U.S. Secretary of State Mike Pompeo states that the Russian Federation, through its 2014 invasion of Ukraine and its attempted annexation of Crimea, sought to undermine a bedrock international principle shared by democratic states: that no country can change the borders of another by force.

"As we did in the Welles Declaration in 1940, the United States reaffirms as policy its refusal to recognize the Kremlin's claims of sovereignty over territory seized by force in contravention of international law. In concert with allies, partners, and the international community, the United States rejects Russia's attempted annexation of Crimea and pledges to maintain this policy until Ukraine’s territorial integrity is restored," reads Pompeo's statement.

In this document, the United States calls on Russia to respect the principles to which it has long claimed to adhere and to end its occupation of Crimea.

The declaration notes that "as democratic states seek to build a free, just, and prosperous world, we must uphold our commitment to the international principle of sovereign equality and respect the territorial integrity of other states."

"Through its actions, Russia has acted in a manner unworthy of a great nation and has chosen to isolate itself from the international community," the declaration says.