'You'll see things happen': Trump to speak with Zelensky tomorrow, hints at new sanctions on Russia

US President Donald Trump will speak with Volodymyr Zelensky on Thursday, a White House official said, after the Ukrainian president and European leaders said earlier that they expected a call.

"I'm having a conversation with him very shortly and I'll know pretty much what we're going to be doing," Trump told an AFP reporter in the Oval Office on Wednesday as Polish President Karol Nawrocki visited.

A White House official later told AFP: "President Trump was referring to Zelensky. They will be speaking tomorrow."

Trump also hinted at fresh sanctions against Russia if it fails to make a Ukraine peace deal, saying that "you'll see things happen" if he is not satisfied with President Vladimir Putin's response.

"Whatever his decision is, we'll either be happy about it or unhappy. And if we're unhappy about it, you'll see things happen," Trump told reporters in the Oval Office as he met Polish President Karol Nawrocki.

Putin earlier today vowed to carry on fighting in Ukraine if a peace deal cannot be reached, striking a defiant tone a day before Kyiv's allies gather in Paris to discuss security guarantees.

Progress towards settling the three-and-a-half-year war appears to have stalled, despite a flurry of diplomatic efforts by US President Donald Trump, who met both his Russian and Ukrainian counterparts last month.

Putin's troops kept up their strikes across the country, firing more than 500 drones and missiles at Ukraine overnight and killing nine in attacks on a frontline town.

The Russian leader hailed his forces' progress, saying they were advancing on "all fronts" and had hobbled Ukraine's army so much it could no longer mount an offensive.

"Let's see how the situation develops. If not, then we will have to resolve all our tasks militarily," Putin told reporters, including AFP, in Beijing, where he had earlier attended a grand military parade alongside China's Xi Jinping and North Korea's Kim Jong Un.

Zelensky was set to head to Paris, where he will hold talks with leaders of the "coalition of the willing," a French-British led initiative seeking to put together security guarantees and a peacekeeping force to protect Ukraine in the event a peace deal can be reached.