Ukraine's new Western-backed prime minister said on Tuesday that his ex-Soviet country had no plans to join NATO following last month's fall in Kiev of a pro-Kremlin regime.

Prime Minister Arseniy Yatsenyuk said in a televised address to the nation that "for the sole purpose of preserving the unity of Ukraine, the issue of (Ukraine's) accession to NATO is not on the agenda."

"The country will be defended by a strong and modern Ukrainian army," Yatsenyuk said.

The new premier -- in power since the February 22 ouster of Moscow-back president Viktor Yanukovych -- is still due to sign in Brussels on Friday the political portion of a landmark EU pact whose rejection by the deposed government in November sparked protests that led to its fall.

Yatsenyuk's comments came as Russian President Vladimir Putin took the first steps to absorb the Ukrainian region after a disputed weekend referendum in which an overwhelming majority of voters backed the Black Sea peninsula splitting from Ukraine and joining Russia.