Mexico's Economy Minister Ildefonso Guajardo said on Thursday he would not allow the United States to use planned tariffs on steel and aluminum imports to pressure the country in ongoing NAFTA talks.

U.S. President Donald Trump plans to offer Canada and Mexico a 30-day exemption from the planned tariffs, which could be extended based on progress in NAFTA talks, a White House official said on Wednesday night.

"This has nothing to do with the negotiations," Guajardo told Reuters on the sidelines of the signing ceremony for an Asia-Pacific trade agreement in Santiago. "Under no circumstance will we be subject to any type of pressure."

Guajardo said Mexico was willing to spend "as much time as necessary" to resolve NAFTA negotiations successfully.

"Mexico will not be leaving the treaty," Guajardo said. "NAFTA exists between three countries. The others are deciding whether they stay or leave, not Mexico."