The talks, scheduled for Sunday in Mexico City, will come a day before the end of a 45-day period in which the Mexican government committed to significantly lowering the number of people trying to cross the US border illegally.

The deal struck in early June averted tariff threats by US President Donald Trump.

On Monday, the Trump administration unveiled a new rule to bar migrants from applying for asylum at the US southern border, requiring them to first pursue safe haven in a third country through which they had traveled.

Ebrard responded that Mexico did not agree with the new asylum rule, and his office suggested Mexico would not cooperate with the program, saying migrants who were not allowed to apply for US asylum should be returned to their home countries, not Mexico.

However, Ebrard said the move would not affect the 45-day agreement between the two countries. He also denied that it would turn Mexico into a de-facto "safe third country," under which Mexico would accept that asylum seekers passing through its territory should seek refuge there, not the United States.

Under the June deal, Mexico agreed to start talks about becoming a safe third country if Washington deems its enforcement measures have not sufficiently lowered immigration flows. Safe third country status would require Mexican Congress approval.

According to Mexico's foreign ministry, migrant apprehensions at the US southern border fell 30% in June from the previous month.