By Steve Holland, Tom Balmforth and Yuliia Dysa WASHINGTON/KYIV (Reuters) -U.S. President Donald Trump on Tuesday said Vladimir Putin was "playing with fire" by refusing to engage in ceasefire talks with Kyiv as Russian forces made gains in Ukraine's northeast.

President Donald Trump could move ahead with new sanctions on Russia in the coming days as he vents frustration at Russian President Vladimir Putin for his aerial assault on Ukraine over the weekend,

Trump's rhetoric on the war in Ukraine started by Putin is continuously shifting, and his latest comments followed