EU defence ministers were preparing to meet Wednesday to discuss a plan to rush one billion euros of ammunition to Ukraine as pressure mounts on Kyiv's allies to boost supplies to its war effort.
Ukraine's critical shortage of ammunition will top the agenda at the meeting in Stockholm, where European leaders will try to replenish the thousands of 155-millimetre howitzer shells Kyiv's forces are firing each day in its fight against a grinding Russian offensive.
Fighting is raging around Ukraine's eastern town of Bakhmut, with president Volodymyr Zelensky warning that if the town fell, Moscow would gain an "open road" for offensives deeper into his country.
"We understand that after Bakhmut, they could go further. They could go to Kramatorsk, they could go to Sloviansk, it would be an open road for the Russians after Bakhmut to other towns in Ukraine, in the Donetsk direction," Zelensky told CNN in an interview due to be broadcast in the United States on Wednesday.
During a visit to Canada, European Commission President Ursula von der Leyen on Tuesday underscored European resolve to ward off Russian aggression.
"We will never accept that a military power with fantasies of empire rolls its tanks across an international border," von der Leyen said in an address to Canada's parliament.
But a report released Tuesday in the New York Times, which claimed that US officials had seen new intelligence indicating a "pro-Ukrainian group" was behind last year's sabotage of the Nord Stream gas pipelines, could raise difficult questions among the allies.
Senior Ukrainian official Mykhailo Podolyak dismissed the report, saying the country "had nothing to do with the Baltic Sea mishap".
Battle for Bakhmut
The Russian army vowed Tuesday to capture Bakhmut -- a salt-mining town with a pre-war population of 80,000.
The intense fighting around the town has been the longest and bloodiest in Russia's more than year-long invasion, which has devastated swathes of Ukraine and displaced millions.
Ukraine said it had identified a soldier who had gone missing in the area being shot dead in a video that sparked outrage on social media and as UN chief Antonio Guterres headed to Kyiv for talks.
The footage shows what appears to be a detained Ukrainian combatant standing in a shallow trench, smoking, and being shot after saying "Glory to Ukraine".
Russia has appeared intent on capturing the town at all costs.
"Capturing (Bakhmut) will allow for further offensive operations deep into the defence lines of the Armed Forces of Ukraine," Russian Defence Minister Sergei Shoigu told military officials during a televised meeting on Tuesday.
Russian mercenary group Wagner has spearheaded the attack on Bakhmut and its head, Yevgeny Prigozhin, who is locked in a rift with Russia's military leadership, appeared to mock Shoigu, saying he had "not seen him" near the battlefield.Zelensky told CNN that his armed forces were resolved to stay in Bakhmut.
"I had a meeting with the chief of staff yesterday and the chief military commanders online and offline ... and they all (say) that we have to stand strong in Bakhmut," he said.
"Of course, we have to think about the lives of our military. But we have to do whatever we can whilst we're getting weapons, supplies and our army is getting ready for the counter-offensive."
Tanks from Poland
Prigozhin estimated that between "12,000 and 20,000" Ukrainian troops were still defending the city.
He said that while "very tough battles are ongoing both day and night", Ukraine's fighters "are not running away".
Ukraine got a boost on Tuesday when its western neighbour and steadfast ally Poland announced it was sending 10 promised Leopard tanks this week.
Both sides have said the Bakhmut battle has cost a significant number of troops, though neither has given figures.
Outside the town, a Ukrainian soldier told AFP that Kyiv was losing control.
"Bakhmut will fall," one exhausted soldier said Monday in the town of Chasiv Yar, 10 kilometres (six miles) west of the front line.
Some units had started to retreat in "small groups", he said.
Ukrainian officials say around 4,000 civilians remain in the town, which has been virtually flattened.
"Approximately 38 children, as far as we know, remain in Bakhmut," deputy prime minister Iryna Vereshchuk told regional media on Tuesday.
Belarus detains sabotage group
Amid fears of Moscow-allied Belarus, Ukraine's northern neighbour, entering the conflict, Minsk accused Kyiv's secret services on Tuesday of being behind a partisan plot to damage a Russian military plane in the country last month.
Longtime leader Alexander Lukashenko said 20 people had been detained in connection with attacking the plane. Regime opponents said partisans damaged the jet at an airstrip near the capital Minsk last month.
Lukashenko identified the main culprit as a dual Russian-Ukrainian citizen.
Lukashenko, who allowed his Russian ally Vladimir Putin to use Belarusian territory as a launchpad for his Ukraine invasion a year ago, said the alleged culprit was a "terrorist."