KYIV — U.S. President Donald Trump finally labeled Russia the aggressor in the war against Ukraine, further demonstrating a hardening of his position toward Moscow.

Referring to Ukrainian and Russian troop casualties, Trump told reporters Sunday: “8,000 soldiers have died this week, from both countries. Some more from Russia, but when you’re the aggressor, you lose more.”

Trump has previously refused to condemn Moscow for the invasion, with his administration siding with Russia and North Korea in February to reject a U.N. motion backing Ukraine’s territorial integrity and condemning Russia. The U.S also objected to a G7 statement calling Russia an aggressor in February. Trump has blamed Ukraine for the war, saying in April: “You don’t start a war against someone 20 times your size and then hope that people give you some missiles.”

But Trump’s stance toward the Kremlin has changed over the summer, with his administration exerting increasing pressure on Vladimir Putin as the Russian president stonewalls Trump’s efforts to broker direct peace talks with Ukraine’s Volodymyr Zelenskyy.

“I stopped seven wars, and I thought this one was going to be easy for me, but this has turned out to be tough,” Trump said Sunday, referring to the Russian invasion. “I think I have to do all the talking. They [Zelenskyy and Putin] hate each other. They hate each other so much they can’t breathe.”

With Trump’s tougher stance failing to push Putin to the negotiating table with Zelenskyy, the U.S. administration is facing increasing calls to impose harsher sanctions on Russia. Trump on Sunday claimed he planned to do so — but only after Europe stops buying Russian oil and toughens its own sanctions regime.

While Trump said European countries are his “friends,” they are still “buying oil from Russia. I don’t want them to buy oil. And the sanctions that they are putting on are not tough enough.”

Hungary and Slovakia are the EU’s top purchasers of Russian energy and have opposed the European Commission’s efforts to phase it out.

On Friday, U.S. Secretary of Energy Chris Wright told POLITICO that the U.S. wants “to displace all Russian gas,” saying: “The more we can strangle Russia’s ability to fund this murderous war, the better for all of us.”