Turkey on Tuesday said nothing can justify Russia's actions in Ukraine and other ex-Soviet states, in a rare strong criticism of its increasingly close ally ahead of a NATO meeting.

Turkish Foreign Minister Mevlut Cavusoglu, whose country is a key member of NATO, said Ankara was prepared to play a "constructive role" in the disputes between Russia and the West over Ukraine.

But he said: "Nothing can justify what Russia has been doing in its neighbourhood."

"Ukraine. Crimea. Georgia," he said, referring to the fighting in Ukraine, Russia's 2014 annexation of Crimea and its recognition of two breakaway regions of Georgia after a 2008 war.

He also reaffirmed Ankara's concerns over the Muslim Tatar minority, a Turkic people with strong connections to Turkey who feel sidelined and repressed under the new Russian rule in Crimea.

Cavusoglu said a group of Turkish lawmakers had visited Crimea to look at the situation of the Tatars and would make public their conclusions.

But he also said that the West had made mistakes in presenting Ukraine with a stark choice between Europe and Russia.

"Unfortunately while the Berlin Wall has fallen, the wall in our minds has not."

Turkey's ties with Russia have warmed in recent months as it goes through a cool period in relations with the European Union.

The two sides are also working on an ambitious project for a new Black Sea gas pipeline and Turkey has been relatively restrained in its criticism of Russia's actions in Ukraine.

But Cavusoglu said along with the threat posed by Islamic State jihadists, the threat from the "east" would be a key issue at the two-day NATO foreign ministers meeting starting Wednesday in Antalya.

The West accuses Russia of arming separatists in eastern Ukraine and even sending its own troops across the border. Russia denies the charges.