United States President Donald Trump said on Sunday that the Federal Bureau of Investigation had failed to act on a warning about Nikolas Cruz, the teenager accused of killing 17 people at a school in Florida, because the agency spent time trying to prove Russian collusion with the Trump campaign during the 2016 elections.

Trump also claimed that he never said that Moscow had not interfered in the US elections. “I said ‘it may be Russia, or China or another country or group, or it may be a 400 pound genius sitting in bed and playing with his computer,’” the president said. “The Russian ‘hoax’ was that the Trump campaign colluded with Russia – it never did!”

Instead, Trump claimed that former US President Barack Obama knew about the Russian threat to the polls and “did nothing” about it.

The US president also alleged that it was Russia’s goal to “create discord, disruption and chaos within the US”. He claimed that the investigation into alleged meddling by Moscow meant that the Russians had “succeeded beyond their wildest dreams”.