CNN reports that U.S. administration officials are scrambling to turn President Donald Trump's unexpected decision to meet with North Korean leader Kim Jong-un into a reality.

The report cites an administration official as saying the White House will convene a meeting Tuesday to discuss preparations and that Secretary of State Rex Tillerson cut short a trip to Africa to "get his hands around what's happening." 

CNN said that Tillerson and other senior officials have also reached out to allies worldwide and lawmakers on Capitol Hill.

Earlier, regarding the North Korea summit, White House spokeswoman Sarah Huckabee Sanders said the administration is preparing on a "number of levels" and an "inter-agency process" which she declined to describe further.