OTTAWA -- Conservative Leader Andrew Scheer says nations that believe in free trade need to present a united front against the protectionist moves coming out of the United States.

Scheer is in London meeting British politicians to promote a promise that if he is elected prime minister next year he will prioritize a free-trade agreement with the United Kingdom after it officially leaves the European Union.

However, he says a hot topic at most meetings is President Donald Trump's proposal to impose steel and aluminum tariffs, which may be signed later today.

Scheer says countries like Canada, the U.K. and other members of the European Union which are committed to free trade need to stick together and convince the United States not to move forward with steel or any other new tariffs.

He says protectionism might appeal in the short term to people or communities who are struggling, but he says evidence shows long-term free trade is the best way to increase employment.

Scheer says his party is very concerned about the status of NAFTA negotiations and while he says any Canadian government would be challenged to deal with the Trump administration, the Liberals could have eased some anxieties by putting contingencies in the recent budget in the case NAFTA talks go badly.