A top White House official said Sunday that President Donald Trump is "deadly serious" about imposing tariffs on imports from Mexico, but acknowledged there are no concrete benchmarks being set to assess whether the US ally is stemming the migrant flow enough to satisfy the administration.
"We intentionally left the declaration sort of ad hoc," Mick Mulvaney, the acting White House chief of staff, said on "Fox News Sunday."
"They have to get dramatically better and they have to get better quickly." He said the idea is to work with the Mexican government "to make sure that things did get better."
The president "has been known to play with fire, but not live hand grenades," Kennedy said on CBS's "Face the Nation."