Donald Trump (Photo: Al Drago/EPA)

President Donald Trump said he had learned "interesting things" but would make them public later. He made the statement at a briefing at the White House when asked if he had recently spoken with Russian dictator Vladimir Putin.

"Yes, I don't want to... I have learned things that will be very interesting. I think you'll find out in the coming days," the US President said, without disclosing details.

Trump also clarified the consequences for Putin of refusing to meet with President Volodymyr Zelenskyy.

"We'll see what happens. We'll see what they do and what happens," he said .

The US president added that he was watching "this closely." According to him, Russia and Ukraine allegedly lost more than 7,000 soldiers last week. He said he wants it to end.

Trump says he had a "very good meeting" with Putin in Alaska a few weeks ago.

"Let's see if this will have any effect. If not, we will change our approach," he emphasized.