Democratic US House Speaker Nancy Pelosi warned Tuesday that Congress would not consider the trade accord meant to replace NAFTA until Mexico enacts labor reform.

"Unless you do this, we can't even consider it. ... We have to see that (Mexico passes) the legislation, that they have the factors in place that will make sure it's implemented and they demonstrate some commitments in sincerity, because it's a big issue how workers are treated in Mexico," said Pelosi in an interview with the daily Politico.

President Donald Trump hopes Congress will ratify by August the pact that emerged from the renegotiation of the 1994 North American Free Trade Agreement linking the economies of the US, Mexico and Canada.

Members of the Democratic majority in the House are interested in changing some elements of the US-Mexico-Canada Agreement (USMCA), mainly in the areas of labor enforcement and environmental standards.

In the interview, Pelosi said she agrees with her fellow Democrats that they should make changes to the USMCA to ensure it is enforceable.

She said that it would "take some time" to vote on the USMCA in the House, where she is the official who selects the bills that are brought up for debate.

Senate Finance Chairman Chuck Grassley advised Trump last week to cancel the tariffs on imports of steel and aluminum from Mexico and Canada to facilitate ratification of USMCA.

Grassley said he had advised Trump directly in a recent meeting, but the President had decided to refuse the request.

"It's just time until the president wakes up. I don't know why it's taken him so long to realize he's got a victory at hand. Just take these tariffs off," said Grassley, according to Politico.

Trump and his advisers, including US Trade Representative Robert Lighthizer, are refusing to cancel the tariffs until both countries accept export quotas for the metals.

The government of Mexican President Andres Manuel Lopez Obrador announced they it will approve legislation to ensure ratification of the agreement before that country's Congress goes on recess at the end of April.