If Mattis was aware that Trump was going to announce a suspension of military exercises, he apparently did not share that information with the South Koreans or with the military organization most directly affected: U.S. Forces Korea.
That U.S. command said it had "received no updated guidance on the execution or cessation of training exercises."
The South Korean government also appeared caught off guard. Seoul's presidential office told The Associated Press that it was trying to parse Trump's comments. The South Korean military seemed similarly surprised.
"At this current point, there is a need to discern the exact meaning and intent of President Trump's comments," Seoul's Defense Ministry said, adding that there have been no discussions yet with Washington on modifying drills set for August.
A degree of confusion arose after Vice President Mike Pence spoke to senators at a lunch closed to media coverage. Sen. Cory Gardner, Republican of Colorado, said Pence indicated that "exercises will continue," although Sen. Rand Paul, a Kentucky Republican, said this referred to routine, daily training in South Korea, not the large-scale war games that Trump said are suspended.