US President Donald Trump meets with Ukrainian President Volodymyr Zelenskyy during the United Nations General Assembly on Tuesday. (Source: AP)US President Donald Trump on Monday said he believes NATO members should shoot down Russian aircraft if they violate allied airspace. On Friday, three Russian MiG-31 fighter jets entered Estonian airspace over the Gulf of Finland without permission. A week earlier, Polish officials reported that Russian drones and fighter jets crossed into their airspace, prompting NATO forces to scramble F-15 and F-35 jets in response. The statement followed an emergency session of the United Nations Security Council, which saw heated exchanges over the issue.