Guns were silent in eastern Ukraine into Saturday, as a truce signed Friday in the Belarusian capital, Minsk appeared to be holding.

"It is, at the most, a beginning of the end of the crisis," German Foreign Minister Frank-Walter Steinmeier said in Saturday's edition of Germany's "Bild" newspaper, adding that whether or not the weapons would be silenced permanently would depend on the will of Moscow and Kyiv to resolve the remaining open questions politically.

Those questions include the future state of the separatists' self-proclaimed republics.

Under the Minsk deal, prisoner exchanges and the pulling back of troops by both sides were due to begin Saturday. Russia was also allowed to supply aid to cities which had been caught up in the violence. However, a senior separatist leader said the mainly Russian-speaking regions in Ukraine's east still wanted to formally break away.

"The ceasefire does not mean a change in our goal to split from Ukraine," envoy for the separatists, Igor Plotnitsky told reporters in Minsk.

The truce deal was largely based on a plan put forward by Russian President Vladimir Putin. Moscow has repeatedly denied claims that it is arming the separatists or sending in its own troops.

More than 2,600 people have been killed during fighting in eastern Ukraine since April, when pro-Moscow rebels took over local administrative facilities in the country's industrial heartland.

Sanctions and NATO

The European Union planned new sanctions for Russia despite the deal, though the sanctions may be withdrawn if peace prevails.

NATO also approved a "spearhead" force of thousands of soldiers to maintain a presence across eastern European nations who had feared facing a similar situation to Ukraine.

"This decision sends a clear message - NATO protects all allies at all times," the alliance's outgoing chief Anders Fogh Rasmussen said.

Estonia tensions over detained officer

Meanwhile, Estonia on Friday said one of its border security service officers was abducted by unknown gunmen and taken across the border to Russia.

However the Russian Federal Security Service said the Estonian was detained in Russia's Pskov region and was suspected of being a spy.

Relations between Russia and Estonia - an ex-Soviet state and now EU and NATO member - have become tense in recent months due to the Ukraine conflict.

Earlier this week, US President Barack Obama visited Estonia and assured it would receive NATO protection from any Russian threat.

se/hc (AP, Reuters, AFP)