Speaking in Brussels on Wednesday, NATO Secretary General Anders Fogh Rasmussen downplayed promising signs of compliance from Russia in recent days, insisting that Moscow had done little to support peace efforts in Ukraine. The comments were delivered ahead of a meeting of foreign ministers from NATO member states.

"I regret to say that we see no signs that Russia is respecting its international commitments," Rasmussen told reporters.

"Today, we will review our relations with Russia and decide what to do next," he added.

Since Ukrainian President Petro Poroshenko's ceasefire was put into place last Friday, Russian President Vladimir Putin has appeared to be more willing to offer his support to the government in Kyiv. The Russian leader urged the pro-Russian separatist rebels in Ukraine's east to engage in dialogue with Kyiv and also said he would support implementing a peace plan.

On Wednesday, The Russian parliament also cancelled a March 1 authorization which allowed Putin to deploy troops to Ukraine. The decision was made in response to his personal request, filed the previous day.

However, an attack on a Ukrainian helicopter by pro-Russian separatists on Tuesday night, killing nine people, raised fears that clashes in the eastern European country were far from over.

Russia could face more sanctions

A failure on Russia's part to play a more active role in defusing the crisis in Ukraine could provoke further EU sanctions, the British foreign minister warned on the sidelines of the NATO meeting.

"While there have been welcome words from Russia about that (the peace plan) we have not seen yet the actions to go with that, including tragically the shooting down of a Ukrainian helicopter yesterday with the death of nine more people," UK Foreign Secretary William Hague told reporters on Wednesday.

"The absence of that action by Russia [will make] the case for stronger sanctions from European Union nations [even stronger]," Hague said.

German Foreign Minister Frank-Walter Steinmeier also weighed in, warning how quickly the crisis could worsen.

The helicopter attack showed "how fragile the situation is and how quickly recent signs of progress can be undone by the separatists," he said.

EU foreign ministers are due to meet on Friday to deliberate over further action against Russia.

kms/rc (AP, AFP, Reuters, dpa)