North Korea has been using cyberattacks on banks and cryptocurrency exchanges to steal an estimated $2 billion, a U.N. report claims.

The confidential report, seen by Reuters, claims the heavily sanctioned country has been using the money to fund its weapons program, which includes building weapons of mass destruction.

The report, which cites independent experts monitoring the situation, says North Korea has been launching "increasingly sophisticated attacks to steal funds from financial institutions and cryptocurrency exchanges to generate income," as well as using cyberspace to launder the money. The experts are looking into at least 35 reported cyberattacks in 17 countries.

North Korea did not respond to Reuters' request for comment. The country's leader Kim Jong Un met with U.S. President Donald Trump three times, with the two sides agreeing they will resume talks on Pyongyang shutting down its nuclear weapons program (the talks are yet to materialize).

The U.S. State Department did respond, saying it calls "upon all responsible states to take action to counter North Korea’s ability to conduct malicious cyber activity, which generates revenue that supports its unlawful WMD and ballistic missile programs.”

Cryptocurrency theft has been a common occurrence throughout the space's short history, and it showed no signs of stopping in recent years, with crypto exchanges being a big target. Just this year, hackers stole $40 million from Binance, $32 million from Bitpoint, and $4.2 million from Bitrue, to name a few.

According to U.N. experts, stealing from cryptocurrency exchanges made it easier for North Korea to avoid being tracked.

This is not the first time North Korea has been accused of cyberattacks. In September 2018, an alleged North Korean spy was charged of hacking Sony Pictures Entertainment's servers in 2014. A 2017 report claimed North Korean hackers have stolen about $88,000 worth of bitcoin between 2013 and 2015.