South Korea’s president asked the United States to reduce North Korea sanctions in return for an agreement to halt Pyongyang’s nuclear weapons program.

In an interview with The New York Times, Lee Jae-myung said: “I believe that the exchange between sanctions that in any case are not very effective and stopping the construction of nuclear weapons and long-range ballistic missile technology is of great value.”

According to him, based on South Korea’s assessments, North Korea now has the capability to produce another 10 to 20 nuclear weapons per year, or may be producing them. Lee warned that when Pyongyang believes it has amassed enough weapons, it will be tempted to export these weapons to earn revenue.

Donald Trump, the U.S. president, is pursuing a renewed meeting with Kim Jong Un, the leader of North Korea.