The peso was tumbling Thursday after Mexico's president, Enrique Peña Nieto, announced he had canceled a meeting scheduled for next week with President Donald Trump.
The peso was down by 1.2% at 21.3175 per dollar as of 11:57 a.m. ET.
The currency had been up by as much as 0.8% at 20.9358 per dollar at about 8:50 a.m. ET.
"This morning we have informed the White House that I will not attend the meeting scheduled for next Tuesday with the @POTUS," Peña Nieto tweeted, according to an online translation.
That followed a tweet sent earlier on Thursday morning from Trump's personal Twitter account that said: "The U.S. has a 60 billion dollar trade deficit with Mexico. It has been a one-sided deal from the beginning of NAFTA with massive numbers of jobs and companies lost. If Mexico is unwilling to pay for the badly needed wall, then it would be better to cancel the upcoming meeting."