First Quantum CEO Tristan Pascall flew to Panama over Christmas to attend the meeting in person with the minister, Federico Alfaro, Reuters sources say.
The deal includes a silver stream on the Esperanza project in Morelos, Mexico and royalties on the Fenn Gib South, Ronda and Northshore West exploration-stage projects in Ontario.
The company announced it will defer completing the facility's rare earth hydrometallurgical leaching, purification and rare earth precipitation circuits until 2024.