Kyiv (Ukraine) (AFP) - Ukrainian President Volodymyr Zelensky said Saturday that a counteroffensive was underway as Canadian Prime Minister Justin Trudeau visited Kyiv and criticised Russia over flooding from the breached Kakhovka dam.

"Counteroffensive and defensive actions are taking place in Ukraine: at which stage I will not talk in detail," Zelensky said at a joint press conference in Kyiv with Trudeau.

Zelensky commented after Russian President Vladimir Putin claimed that Kyiv's long-expected counteroffensive was already failing.

Russia has reported thwarting Ukrainian attacks in the east and south.

"It's interesting what Putin said about our counteroffensive. It is important that Russia always feels this: that they do not have long left, in my opinion," Zelensky said.

He added that he was in daily touch with military commanders, including armed forces chief Valery Zaluzhny, and "everyone is positive now -- tell that to Putin!"

Trudeau, 51, and Zelensky, 45, hugged each other and used each other's first names as the Canadian leader made his second unannounced visit to Kyiv since full-scale war broke out in February last year.

When asked later Saturday why he stopped short of blaming Russia for the dam collapse, Trudeau said: "I know there are investigators and there are a lot of questions and intelligence being analysed on what exactly happened to have this dam collapse. 

"But there is no doubt in my mind that absent Russia's invasion of last February, that dam would still be standing today."

And speaking about Putin, he added: "He is not someone that I have a particular level of trust or interest in."

Canada, which hosts a large Ukrainian diaspora, has been one of Kyiv's key allies since the Russian invasion.

It has provided Ukraine with significant military aid, trained more than 36,000 soldiers and adopted sanctions against Moscow.

'Direct consequence'

Trudeau denounced Russia's role in the destruction of the Russian-controlled Kakhovka dam in southern Ukraine on Tuesday.

The flooding from the breached dam has forced thousands to flee their homes and sparked fears of humanitarian and environmental disasters.

Ukraine accuses Russia of blowing up the dam, while Moscow says Kyiv fired on it.

In his daily address, Zelenksy condemned the "shameful indifference" from the international community to the fallout of the dam's destruction, including the failure to "form and send a rescue mission to the occupied territory" or "come out with clear and strong statements condemning this latest Russian war crime."

He urged international organisations to come to the aid of those in Russian-occupied territories.

Pledging 10 million Canadian dollars (US $7.5 million) in new funding for flood relief, Trudeau said Russia "will be held to account" for its actions in Ukraine.

The Canadian leader said he would provide 500 million Canadian dollars in new funding for military assistance to Ukraine.

He also pledged Canada would be part of the multinational efforts to train Ukraine's fighter pilots.

Earlier in the day Trudeau placed flowers by a wall of remembrance displaying the faces of soldiers killed in combat while a military orchestra played.

He also visited an open-air exhibition featuring destroyed Russian military vehicles.

Ukrainian Deputy Defence Minister Oleksandr Polishchuk handed Trudeau a box that he said held shrapnel from a rocket that fell on the Black Sea port city of Odesa.

He said the gift was intended to remind Trudeau of Ukraine's suffering from Russian strikes.

Iran must 'end support' for Russia

Three people were killed early Saturday in a fire sparked by debris from shot-down Russian drones in the Odesa region.

French President Emmanuel Macron urged his Iranian counterpart Ebrahim Raisi to "immediately end" Tehran's support for Russia's invasion of Ukraine, which involves supplying Moscow with attack drones, the Elysee said.

Macron in a telephone call underlined the serious "security and humanitarian consequences" of Iran's drone deliveries "and urged Tehran to immediately end the support it thus gives to Russia's war of aggression against Ukraine", said a statement.

The call came a day after White House national security spokesman John Kirby said Russia was receiving materials from Iran to build a drone factory on its territory that "could be fully operational early next year".

The United States has said that Russia has received hundreds of Iranian attack drones to attack Kyiv and "terrorise" Ukrainians, a charge denied by Tehran.