MEXICO CITY (AP) — Mexico, the United States and Canada have begun a second round of talks on re-negotiating the North American Free Trade Agreement.

Officials are expressing optimism despite U.S. President Donald Trump's suggestions he could withdraw his country from the 23-year-old trade pact.

Gerardo Gutierrez Candiani is head of Mexico's special economic zones agency. He says "there are conditions to negotiate, despite some statements."

Gutierrez Candiani adds that issues on the table include labor standards, local content rules and dispute resolution mechanisms.

The U.S. opposes the current system of private arbitration panels. Gutierrez Candiani said Friday that "they are not agile enough, and mechanisms have to be sought that are more agile, more reliable."

The first round of talks took place in Washington in mid-August.