Mexico's Foreign Minister Jose Antonio Meade has met with the US ambassador after summoning him for the second time in less than two months over claims Washington spied on Mexican leaders.

A foreign ministry official said Meade held talks with Ambassador Earl Anthony Wayne on Thursday over a German magazine's report that the National Security Agency hacked the emails of former president Felipe Calderon while in office.

The official refused to give any details of the conversation, but Meade urged the United States this week to expand an investigation into spying to include the allegations reported by Der Spiegel.

Mexico had already summoned Wayne last month and asked for a US investigation over allegations the NSA had snooped on President Enrique Pena Nieto's emails when he was running for office last year.

The Mexican interior ministry announced this week it was launching its own probe to determine whether any Mexicans were involved in the alleged spying.