MEXICO CITY — Mexican President Enrique Pena Nieto says reported surveillance by the U.S. National Security Agency would constitute an illegal act.

Pena Nieto demanded the United States investigate the allegations aired in a report Sunday night on Brazil’s Globo TV.

The report cites 2012 documents from NSA leaker Edward Snowden indicating the U.S. monitored Pena Nieto’s communications before he was elected in July 2012.

Pena Nieto spoke to reporters Monday at Canada’s Gander International Airport in Newfoundland on a stopover during his trip to Russia for a G-20 summit.

Pena Nieto said that “if proved … it is an act outside the law.” He said he may discuss the issue with President Barack Obama at the summit.

On Monday, Mexico’s foreign ministry said it summoned the U.S. ambassador to express Mexico’s concerns.

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