Sri Lanka, March 31 -- Donald Trump has warned of imposing secondary tariffs of up to 50% on countries buying Russian oil if Russian President Vladimir Putin does not agree to a ceasefire in Ukraine.

In an NBC News interview, Trump said he was "very angry" and "pissed off" at Putin for questioning Ukrainian President Volodymyr Zelensky's credibility. He also threatened a 25% tariff on Russian oil and other products sold in the US if Moscow fails to halt the war.

The comments mark a shift in Trump's approach toward Russia, as European leaders had feared he was aligning too closely with Putin. Over the past six weeks, Trump has pressured Zelensky for concessions while engaging with Putin, but his latest stance signals a tougher approach....