The off-the-cuff remark prompts Russia to call the comment "unforgiveable rhetoric".
source https://www.bbc.co.uk/news/world-us-canada-60773626?at_medium=RSS&at_campaign=KARANGA
source https://www.bbc.co.uk/news/world-us-canada-60773626?at_medium=RSS&at_campaign=KARANGA