Mexican opposition leaders have called upon President Pena Nieto to cancel his trip to the United States scheduled for next week.
Mexican President Enrique Pena Nieto on Wednesday condemned US President Donald Trump's decision to order construction of a border wall.
"I regret and condemn the decision of the United States to continue construction of a wall that, for years, has divided us instead of uniting us," Pena Nieto said in a brief televised message.
Trump issued an executive order earlier on Wednesday aiming to speed the construction of the wall.
Pena Nieto did not say whether or not he will attend a summit with Trump in Washington that the White House said would take place on Tuesday.
But the opposition politicians urged him on Wednesday to call off the trip.
"The position is very clear," said Ricardo Anaya Cortes, president of the conservative opposition National Action Party.
Trump has vowed to force Mexico to pay for the wall, and also to renegotiate the North American Free Trade Agreement. Pena Nieto and other officials have repeatedly said Mexico will not pay.