President Donald Trump said tariffs scheduled to hit Canada and Mexico next month are currently “on time” and “moving along very rapidly” following an initial delay, even as a U.S. official cautioned that the schedule may be less certain.

As he fielded questions during a joint press conference with French President Emmanuel Macron, Trump was asked if the tariffs, which he delayed until March 4, will go into effect next week. Canada and Mexico have implemented new border measures in an effort to stave off the tariffs, which Trump says he is levying to halt flows of undocumented migrants and illegal drugs such as fentanyl. “The tariffs are going forward on time, on schedule,” Trump responded. But following the remarks, a U.S. official, who spoke on the condition of anonymity, said the fate of the special 25 percent levy on Canada and Mexico—tied to border security demands—is yet to be determined.