The United States-Mexico-Canada Agreement was signed in November 2018 but formal U.S. approval has been held up by Democratic lawmakers pressing the Trump administration for changes, including steps on drug protections.

Employment Minister Patty Hajdu will be in the meeting to try to address labour enforcement standard concerns.

Robert Lighthizer has agreed to refrain from sending Congress formal ratification language until the Democratic leader was ready to move forward.

The deal could face risks if not ratified before the Canadian election and the American primaries starting shortly afterwards, says one business leader.

U.S. President Donald Trump wrote in a letter to Democratic congressional leaders that lawmakers should pass the United States-Mexico-Canada trade pact before taking up any infrastructure bill.

"They're totally not aware of this ... and the price we're paying," says Liberal MP Mark Eyking, who is leading a trade visit to Washington.

Andrew Leslie, parliamentary secretary to Canadian Foreign Minister Chrystia Freeland, indicated he was not worried when asked about ratification of the treaty.