Donald Trump on Thursday kick-started the process of ratifying the new North American trade pact, but the US president put the accord at risk by announcing tariffs on Mexico over illegal immigration.
Trump could put the text of the agreement before US lawmakers in 30 days, but the timing of the vote is up to Congress.
Canadian Prime Minister Justin Trudeau and Mexican President Andres Manuel Lopez Obrador also submitted the trade pact to their legislatures this week.
The three countries signed the US-Mexico-Canada Agreement in November, to update the 25-year-old North American Free Trade Agreement, and Trump this month cleared a major stumbling block to approval by removing contentious US tariffs on Canadian and Mexican steel and aluminum. 
But the US president was quick to erect a new potential barrier to the accord, on Thursday announcing “a 5% Tariff on all goods coming into our Country from Mexico, until such time as illegal migrants coming through Mexico, and into our Country, STOP.
“The Tariff will gradually increase until the Illegal Immigration problem is remedied,” Trump wrote on Twitter.
Acting White House chief of staff Mick Mulvaney tried to separate the two issues,…