KYIV, Ukraine >> Ukrainian President Volodymyr Zelenskyy said today that counteroffensive and defensive actions are underway against Russian forces, asserting that his top commanders are in a “positive” mindset as their troops engaged in intense fighting along the front line.

The Ukrainian leader, at a Kyiv news conference alongside Canadian Prime Minister Justin Trudeau, responded to a question about Russian President Vladimir Putin’s comment a day earlier that Ukraine’s counteroffensive had started — and Ukrainian forces were taking “significant losses.”

Zelenskyy said that “counteroffensive, defensive actions are taking place in Ukraine. I will not speak about which stage or phase they are in.”

Top Ukrainian authorities have stopped short of announcing a full-blown counteroffensive was underway, though some Western analysts have said fiercer fighting and reported use of reserve troops suggests it was.

“I am in touch with our commanders of different directions every day,” he added, citing the names of five of Ukraine’s top military leaders. “Everyone is positive. Pass this on to Putin.”

Trudeau, the first foreign leader to visit Ukraine since devastating floods caused by a breach in a Dnieper River dam, offered up monetary, military and moral support. He pledged 500 million Canadian dollars ($375 million) in new military aid, on top of more than 8 billion Canadian dollars ($6 billion) that Canada has already provided since the war began in February 2022, and announced 10 million Canadian dollars ($7.5 million) for humanitarian assistance for the flood response.

Trudeau said the dam’s collapse was “a direct consequence of Russia’s war,” but he didn’t blame Moscow directly.

Ukraine’s General Staff said today that “heavy battles” were ongoing, with 34 clashes over the previous day in the country’s industrial east. It gave no details but said Russian forces were “defending themselves” and launching air and artillery strikes in Ukraine’s southern Kherson and Zaporizhzhia regions.

Recent Western injections of billions of dollars’ worth of military equipment — some of it high-tech and top-of-the-line — to Ukraine has raised expectations about when it would be used, and to what effect against dug-in Russian lines.

For months, Ukrainian commanders in the eastern city of Bakhmut — which was largely devastated in a months-long fight that has been one of the bloodiest battles of the war — have used the language of counteroffensive and defensive operations to describe the activity there.

Ukrainian Deputy Defense Minister Hanna Maliar said Friday that the epicenter of the fighting has been in the east, particularly in the Donetsk region, and cited “heavy battles” in Lyman, Bakhmut, Avdiivka and Marinka.

Valerii Shershen, a spokesperson for Ukraine’s armed forces in Zaporizhzhia, told Radio Liberty that they were searching for weaknesses in Russia’s defense in that region, to the west.

Ukraine’s nuclear energy agency Energoatom said the last operating reactor at the Zaporizhzhia nuclear power plant, Europe’s largest, had been placed in “cold shutdown” mode. That’s a process in which all control rods are inserted into the reactor core to stop the nuclear fission reaction and generation of heat and pressure.

The plant’s other five reactors already were in cold shutdown amid concerns about the plant’s exposure to the fighting.

Energoatom said in a statement late Friday that there was “no direct threat” to the Zaporizhzhia plant because of the breach of the Kakhovka dam further down the Dnieper River, which has forced thousands of people to flee flooding and also sharply reduced water levels in a reservoir used to help cool the facility.

Water levels in the Kakhovka reservoir, which feed the Zaporizhzhia plant, remained stable today, Energoatom said.

The site’s power units have not been operating since September last year. The head of the International Atomic Energy Agency is due to visit Ukraine in the coming days.

Ukrainian authorities reported today that at least six civilians have died across the country as Russian forces launched Iranian-made Shahed drones, missiles, and artillery and mortar strikes.

Ukraine’s State Emergency Service reported that three people were killed and more than two dozen wounded overnight in an attack targeting the Black Sea port of Odesa. A spokesperson for Ukraine’s southern operational command, Natalia Humeniuk, said two children and a pregnant woman were among those wounded.

Two people were killed in a Russian attack on the town of Orekhova in the Zaporizhzhia region, according to Gov. Yuriy Malashko.

In Ukraine’s northeast, a 29-year-old man was killed as more than 10 drones targeted the Kharkiv region, its governor, Oleh Syniehubov, reported today. He added that at least three other civilians were wounded.

The Ukrainian air force said that during the night, it had shot down 20 out of 35 Shahed drones and two out of eight missiles “of various types” launched by Russian forces.

The fighting and civilian casualties took renewed attention as authorities in southern Ukraine said water levels have been declining in a vast area beneath the ruptured dam.

Nearly one-third of protected natural areas in the Kherson region could be obliterated by flooding following the breach of the Kakhovka dam, the Ukrainian environment minister warned today.

The U.N.’s humanitarian aid chief, Martin Griffiths, said in an Associated Press interview Friday that an “extraordinary” 700,000 people were in need of drinking water.

In other developments:

German Chancellor Olaf Scholz said today he wants to continue speaking with Putin — whose order for Russia’s invasion of Ukraine has been criticized by many Western leaders — and plans to do so again “soon.” Scholz has spoken several times by phone with Putin since the invasion.

The chancellor said the basis for a “fair peace” between Russia and Ukraine is the withdrawal of Russian troops. “That’s needs to be understood,” he said.

The U.K. government said it will give $20 million in humanitarian aid to those affected by the flooding. Most of the money is being channeled through international organizations such as the Red Cross and the United Nations, and the U.K. is also sending boats, community water filters, water pumps and waders to Ukraine.

The U.K. has already given Ukraine 1.5 billion pounds in economic and humanitarian support since the war began, the government said, and has committed 4.6 billion pounds in military aid.

Jon Gambrell in Kyiv, Joanna Kozlowska and Jill Lawless in London, and Frank Jordans in Bonn, Germany, contributed to this story.