Brazil has argued the visit could have been used to raise suspicions about the electoral system's reliability ahead of October's vote, which the US state department rejects.
President Donald Trump had blamed "sick" vandals, and a former Olympian had been charged, but prosecutors now say contractors caused the damage.
The suspect was working as an intern in Nato's Supreme Headquarters Allied Powers (Shape) Europe in Mons, Belgium.
The US president's comments come after cyber attacks on Minnesota's water systems earlier this week, with US media indicating Iran could be behind it.
Enter your name and email address and subscribe with us to get latest updates.
Brazil's president confirms two US government officials were denied visas over election interference fears
Brazil has argued the visit could have been used to raise suspicions about the electoral system's reliability ahead of October's vote, which the US state department rejects.
Trump administration drops Reflecting Pool vandalism charge and admits 'botched' repairs
President Donald Trump had blamed "sick" vandals, and a former Olympian had been charged, but prosecutors now say contractors caused the damage.
Belgium says a Canadian intern is suspected of spying at Nato. Here's what we know
The suspect was working as an intern in Nato's Supreme Headquarters Allied Powers (Shape) Europe in Mons, Belgium.
Minnesota not Iran to blame for state's water issues, says Trump
The US president's comments come after cyber attacks on Minnesota's water systems earlier this week, with US media indicating Iran could be behind it.