European countries must stop buying Russian oil and gas if they want the United States to tighten sanctions against Moscow, US Energy Secretary Chris Wright said, The Financial Times reports. According to him, the trade in Russian energy resources finances President Vladimir Putin's "war machine." "If the Europeans drew a line and said: ‘We’re not going to buy more Russian gas, we’re not going to buy Russian oil’. Would that have a positive influence on the US leaning in more aggressively [on