Belgrade/Budapest - Hungary would release a "certain" amount of natural gas from its reserves to neighbouring Serbia, President Boris Tadic announced in Belgrade.

Tadic said he arranged with Hungarian Prime Minister Ferenc Gyurcsany for an emergency delivery due to start in mid-afternoon. Only a day before a Serbian delegation returned from Budapest empty- handed, failing to secure a delivery from Hungarian reserves.

In Budapest, Gyurcsany confirmed that Hungary would sell between 1 and 2 million cubic metres of gas to Serbia daily, as long as the situation permits. That amount covers up to one-quarter of Serbia's needs.

"It is a normal human urge to help in a situation like this, so that people in Vojvodina and Serbia are not cold at Christmas time," said Gyurcsany.

Vojvodina, Serbia's northern province, is home to some 300,000 ethnic Hungarians.

Russia this week turned off the valves on Tuesday, after accusing Ukraine of illegally diverting gas from transit pipelines through its territory to Europe.

Virtually all Balkan countries and the broader region were cut off from gas supplies, with Serbia hit particularly hard because of its dependency on the fuel and lack of reserves.

Hundreds of thousands of people were left without heating in their homes amid subzero temperatures, which were expected to plummet to minus 14 degrees celsius by Friday. (dpa)