North Korea warned Tuesday that it is prepared to carry out a nuclear attack against the U.S. if necessary.
The warning: "Our revolutionary strong army is keenly watching every move by enemy elements with our nuclear sight focused...in the U.S. mainland," Rodong Sinmun, the country's official newspaper, said.
Why now: Trump and his administration have argued that placing stricter sanctions on North Korea is the best way to get them to abandon their nuclear program. However, they've said that all options (including military action) are possible, hence the U.S. Navy Strike group sent to waters off the Korean Peninsula.
Twitter take: President Trump started the day with tweets about handling the "North Korean problem," with or without China's help.