In NBC interview, U.S. president threatens to blacklist companies trading with Russia if the Kremlin doesn’t agree to a Ukraine ceasefire.

United States President Donald Trump vowed to impose hefty financial penalties on Russian crude oil imports if Moscow does not sign up to a ceasefire in Ukraine within the next month.

Speaking in an interview with NBC, Trump said he was "very angry" and "pissed off" after Russian leader Vladimir Putin called for the ousting of Ukrainian President Volodymyr Zelenskyy by a United Nations-backed transitional government.

“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 — but if I think it was Russia’s fault, I am going to put secondary tariffs on oil, on all oil coming out of Russia,” the American president said.

The president added that if Russia is unable to make a deal on "stopping bloodshed in Ukraine" - and Mr Trump felt that Moscow was to blame - then he would put secondary tariffs on "all oil coming out of Russia".

"That would be that if you buy oil from Russia, you can't do business in the United States. There will be a 25% tariff on all oil, a 25 to 50-point tariff on all oil," he said.

Mr Trump said Mr Putin knows he is angry, but added that he has "a very good relationship with him" and "the anger dissipates quickly... if he does the right thing".

He said he plans to speak with the Russian president again this week.