Russia said it will cut gas supplies to Europe from Wednesday, in a blow to countries that have supported Ukraine, just as there were hopes that economic pressures could ease after Russia agreed to let Ukraine export grain from Black Sea ports.
The first ships from Ukraine may set sail in days under a deal agreed on Friday, the United Nations said, despite a Russian missile attack on the Ukrainian port of Odesa over the weekend.
Russian energy firm Gazprom announced it is once again reducing gas flows into Germany to allow work on a turbine on the Nord Stream 1 pipeline.
But Ukraine's President Volodymyr Zelensky said this was simply "gas blackmail" against Europe.
The Nord Stream 1 pipeline, which pumps gas from Russia to Germany, has been running well below capacity for weeks.
Earlier this month, Russia's biggest European pipeline was completely shut down for a 10-day maintenance break, sparking fears in Europe that shipments would not resume at all.
Shipments did restart five days ago - albeit still at a reduced capacity. But on Monday, Gazprom announced it would be cutting its gas supply further once again.
During the war, the EU has approved bans on Russian coal and most oil to take effect later this year, but it did not include natural gas because the bloc depends on gas to power factories, generate electricity and heat homes.
Impact far beyond Ukraine
Soaring energy costs and the threat of hunger faced by millions in poorer nations show how the biggest conflict in Europe since World War Two, now in its sixth month, is having an impact far beyond Ukraine.
European Union countries are set to approve on Tuesday a weakened emergency proposal to curb their gas demand as they try to wean themselves off Russian energy and prepare for a possible total cut-off.
The EU executive last week accused Moscow of using energy as a “weapon” and called on 27 member states to accept a voluntary 15% gas savings target, which could become mandatory if Brussels declares a supply emergency.
EU officials had hoped the bloc’s 27 energy ministers meeting in Brussels on Tuesday would rubber stamp the 15% gas savings plan. Instead countries from all corners of Europe have raised objections, led by Spain and Portugal, who are relatively isolated from the EU’s gas pipeline network.
The Kremlin says the gas disruption is the result of maintenance issues and Western sanctions, while the European Union has accused Russia of energy blackmail.
Germany said it saw no technical reason for the latest reduction.
Adding to concerns on the energy front, the Ukrainian state pipeline operator company said Russian gas giant Gazprom without prior notice has increased pressure sharply in a pipeline that runs through Ukraine to deliver Russian gas to Europe.
Such pressure spikes could lead to emergencies including pipeline ruptures, and pipeline operators are obliged to inform each other about them in advance, the Ukrainian company said.
Zelensky slams Moscow
Ukrainian President Volodymyr Zelenskyy said that the cuts showed that Europe should bolster sanctions against Russia.
"This is an open gas war that Russia is waging against a united Europe," Zelenskyy said.
"They don't care what will happen to the people, how they will suffer - from hunger due to blocked ports, from winter cold and poverty ... or the occupation. These are just different forms of terror," he said in his daily video message.
"That is why you have to hit back. Do not think about how to bring back the turbine, but strengthen the sanctions," he said.
Politicians in Europe have repeatedly said Russia could cut off gas this winter, a step that would thrust Germany into recession and hurt consumers already hit by soaring inflation.
Moscow, for its part, says it is not interested in a complete stoppage of gas supplies to Europe.
(with inputs from agencies)
