(COMBO) This combination of pictures created on February 21, 2020 shows US President Donald Trump delivers remarks at a Keep America Great rally in Phoenix, Arizona, on February 19, 2020. Russian President Vladimir Putin delivers a speech during a ceremony in Jerusalem on January 23, 2020 commemorating the people of Leningrad during the Second World War Nazi siege on the city. "Putin will stop killing people if you get energy down another $10 a barrel. He's going to have no choice because his economy stinks," the president told CNBC's "Squawk Box." The rift between Moscow and Washington looks set to...