US president says his Russian counterpart’s questioning of Volodymyr Zelenskyy’s credibility could delay ceasefire

Donald Trump has said he is “pissed off” with Vladimir Putin over his approach to a ceasefire in Ukraine and threatened to levy tariffs on Moscow’s oil exports if the Russian leader does not agree to a truce within a month.

The US president indicated he would levy a 25% or 50% tariff that would affect countries buying Russian oil in a telephone interview with NBC News, during which he also threatened to bomb Iran and did not rule out using force in Greenland.