Russia has resumed pumping crude oil to Europe via Belarus after a three-day halt in supplies.
Oil is now flowing again after a three-day dispute
Russian pipeline operator Transneft began oil flows to Germany and several East European countries at 0530 GMT.
Russia cut off supplies to Belarus on Monday, after claims Minsk had been illegally siphoning off oil.
European nations welcomed the reopening of the key Druzhba pipeline but the International Energy Agency said it had been a "grave" incident.
The European Union Energy Commissioner, Andris Piebalgs, confirmed that all supplies had been renewed and called for "transparent and reliable" behaviour from producer nations and transit countries such as Belarus..
German Foreign Minister Frank-Walter Steinmeier welcomed Moscow's actions, saying Russia had responded to its appeals for a "rapid, constructive resolution".
Poland, which has previously raised concerns over Russian's controls on energy supplies to the EU, said it expected other nations would be more receptive to its worries.
CPS:BOX TITLE="RUSSIAN OIL USERS*" IMAGEORDER="">
Hungary - 83.5% of all oil supplies
Slovakia - 82.2%
Finland - 79.1%
Poland - 77.2%
Czech Republic - 49.3%
Belgium - 31.8%
Sweden - 29.4%
Germany - 26.2%
Netherlands - 25.3%
Italy - 18.1%
Austria - 16.8%
France - 11.4%
Denmark - 2.1%
*Source: Petroleum Economist magazine
International Energy Agency boss Claude Mandil said the supply cut-off undermined faith in Russia as an oil exporter and was "something that should never have happened".
The dispute between the two former Soviet countries came after Moscow forced Belarus to accept a major increase in the cost of gas supplies to the country in late December.
Russia later imposed a hefty duty on oil exports to Belarus, claiming its neighbour was costing it up to $4bn in lost revenues each year.
In retaliation, Belarus slapped a $45-per-tonne transit tax on oil shipments from Russia, but withdrew it earlier on Wednesday after tense top-level government talks between both sides.
Russia had refused to pay the Belarusian tax, and demanded it be cancelled in order for oil supplies through the pipeline to begin again.
At its height, the dispute hit Russian oil supplies to Germany, Poland, Ukraine and other Eastern European countries via the Druzhba pipeline.
The move by Russia to cut off supplies via the Druzhba pipeline - whose name roughly translates as friendship - brought about widespread criticism across Europe.
German Chancellor and current European Union president Angela Merkel denounced the pipeline closure as unacceptable and one that "destroyed trust" in Russia as an energy supplier.
The 2,500-mile-long pipeline has the capacity to ship more than 1.2 million barrels a day to eastern and central Europe and typically works at close to full capacity.