The White House has said that the US is "fully capable" of defending itself against a North Korean ballistic missile attack.
Asked whether North Korea's threat was being taken seriously, a White House spokeswoman said that foreign government's must be "taken at their word".
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Claire Lomas was greeted by cheering supporters after walking through the night to make it to the finish line.
The boy matches no missing persons profile and police say they have yet to find any clues as to his identity.
The prime minister told MPs she was hopeful 'sufficient progress' would be made to move talks on to trade by December.