The announcement came after Russia signed an agreement to end a bitter dispute with Ukraine, which transports Russia gas to Europe via pipeline.

The week long confrontation between Moscow and Kiev interrupted supplies to countries from Turkey to the Baltics during an unusually cold winter. They agreed earlier to a deal which the European Union brokered to end the standoff, but Sunday it looked as if the deal had hit the rocks.

Prime Minister Vladimir Putin said on television the attachment was unauthorized, and "ties up the existing problem (of transit) with issues that have nothing to do with it."

When the monitors are in place, Gazprom will start pumping gas for European consumers, Mr Putin said on Monday, according to Interfax.

Even if a deal is signed, it could take from 10 to 30 hours for gas to be restored, Gazprom officials said, due to the need to rebuild pressure in the pipelines. At the moment, gas supplies are still off.

The agreement does not resolve the dispute between Russia and Ukraine over prices for gas to Europe. It deals only with gas destined for Europe, which has already been paid for.

The dispute has affected the supply of natural gas as far west as Germany and France. About a quarter of Europe's natural gas supply comes from Gazprom.