The Trump administration’s written to Congress, officially triggering the 90-day consultation period required before renegotiation of the North American free Trade Agreement can start.

In the letter, the president’s new trade representative, Robert Lighthizer, gave notice Donald Trump intends to initiate talks ”regarding modernization” of NAFTA.

American Commerce Secretary Wilbur Ross says this notifies ” not just Congress, but all our trading partners, that free and fair trade is the new standard for U.S. trade deals.”

Canadian Foreign Affairs Minister Chrystia Freeland says the three-month notice period has ”long been anticipated” and that the consultation will enable the Trudeau government to assess ”what matters most to Canadians and to advance our interests.”

The White House has offered few details about what changes the U.S. would be seeking, although Trump has recently been critical of lumber and dairy industry trade irritants.