Trump 'very angry' with Putin over ceasefire negotiations

US President Donald Trump has said he is "very angry" and "pissed off" with Russian President Vladimir Putin after six weeks of attempting to negotiate a ceasefire in Ukraine.

In an NBC News interview, he said he was angered by the Russian leader questioning Ukraine President Volodymyr Zelensky's credibility, and he threatened to impose a 50% tariff on countries buying Russian oil if Putin did not agree to a ceasefire.

"If Russia and I are unable to make a deal on stopping the bloodshed in Ukraine, and if I think it was Russia's fault - which it might not be... I am going to put secondary tariffs... on all oil coming out of Russia," he said.

The comments marked a notable shift in the president's tone toward Putin and Russia.

European leaders had worried that Trump was cosying up to Putin as negotiations on a ceasefire in Ukraine continued.

For the past six weeks, Trump has harangued Zelensky in the Oval Office and demanded numerous concessions from Ukraine's president. In turn, he has flattered Putin and largely given in to the Russian president's demands.

This appears to be a departure from that dynamic. It is the first time the US has seriously threatened Russia with consequences for dragging its feet in ceasefire negotiations, which would seem to put the diplomatic ball back in Moscow's court.

NBC News said that in a ten-minute phone interview Trump told them he was very angry and "pissed off" when Putin criticised the credibility of Zelensky's leadership, although the president has himself called Ukraine's leader a dictator and demanded that he hold elections.

"You could say that I was very angry, pissed off, when... Putin started getting into Zelensky's credibility, because that's not going in the right location", Trump said.

"New leadership means you're not gonna have a deal for a long time," he added.

Trump said that the Russians knew of his anger, but noted that he has "a very good relationship" with Putin and "the anger dissipates quickly... if he does the right thing".

If Russia does not follow through with a ceasefire, however, Trump threatened to target their economy further if he thought it was Putin's fault.

"There will be a 25% tariff on oil and other products sold in the United States, secondary tariffs," Trump said, noting that the tariffs on Russia would come in a month without a ceasefire deal.

Secondary tariffs could range up to 50% on goods entering the US from countries still buying oil from Russia. The biggest such buyers by a long margin are China and India.

Trump said he would speak to Putin later in the week.