President Vladimir Putin on Wednesday accused Western countries of creating the Ukrainian crisis and using it to revive NATO.

Speaking after the Western military bloc agreed to boost its presence in eastern Europe, the Russian strongman warned Brussels and Washington against "any hysterics" if Russia chooses to retaliate.

Amnesty International on Wednesday called on Russia to urgently investigate allegations of war crimes in Ukraine and free two prisoners it said were illegally taken across the border.

"We are calling on the Russian government to immediately hand over two of the prisoners they are holding from Ukraine in Russia," Amnesty chief Salil Shetty told journalists in Moscow.

A majority of Europeans and Americans want their governments to support Ukraine, even if that means a risk of greater conflict with Russia, a survey suggested on Wednesday.

In its annual survey of public opinion in 13 major countries, the German Marshall Fund of the United States think tank found that the Ukraine crisis had entrenched mutual suspicion between Russia and the West.

Ukrainian President Petro Poroshenko said Wednesday that Russia had withdrawn most of the troops it allegedly snuck across the border to bolster pro-Kremlin rebels, and vowed greater autonomy for the separatist east in order to sustain a fragile new truce.

The pro-Western leader's comments came just as EU envoys were gathering in Brussels to debate a new wave of sanctions aimed at punishing Russia for its perceived attempts to break up the ex-Soviet state.

Pro-Russian rebels in east Ukraine said on Tuesday they did not have the capability to shoot down Malaysia Airlines flight MH17, after Dutch investigators said it was hit by numerous "high-energy objects".

"I can say only one thing: we simply do not have the military hardware capable of shooting down a Boeing passenger jet such as the Malaysian plane," Alexander Zakharchenko, prime minister of the self-proclaimed Donetsk People's Republic, told Russia's Interfax news agency.

Russia said on Tuesday it hoped that talks on the status of eastern Ukraine would start shortly between Kiev and pro-Moscow rebels.

"We are hoping that the talks will start quickly," Russian foreign minister Sergei Lavrov told reporters, also urging Ukraine to conduct constitutional reforms.

The Russian defence ministry said on Tuesday that its planes had not approached a Canadian frigate on a NATO mission in the Black Sea in an incident Ottawa denounced as "unnecessarily provocative".

Russia's arrest of an Estonian policeman has sparked fears that Moscow is using the incident to test NATO's resolve to defend its small Baltic allies as the crisis in eastern Ukraine rumbles on.

Ukrainian President Petro Poroshenko visited a flashpoint eastern city Monday where sporadic fighting has rattled a three-day-old ceasefire between government and rebel forces.

The highly-symbolic trip to the strategic port of Mariupol came just as EU officials called a new meeting to decide on fresh sanctions against Moscow should the truce fail.

Clad in the blue and yellow of Ukraine's national flag, Irina Dovgan stood on a street of the rebel-held city of Donetsk as passers-by punched, kicked and spat on her, sometimes crushing tomatoes in her bruised face.