North Korean leader Kim Jong Un boasted of North Korea’s nuclear arsenal this week, claiming it serves as a “deterrent” against Western aggression.

“Now, we’ve changed to a country which can defend itself reliably and unwaveringly against high-intensity pressures and military threats and blackmailing by imperialistic reactionaries and hostile forces,” Kim said in a speech Tuesday. “There won’t be any war on this land again and our national security and future will be guaranteed firmly and permanently because of our reliable, effective self-defensive nuclear deterrent.”

Kim’s statements come as nuclear talks with the U.S. have stalled. The Trump administration would like North Korea to pursue a path of denuclearization, while Pyongyang would like Washington to lift the sanctions debilitating the Asian nation’s economy. North Korean and U.S. officials last met in October in Sweden to discuss the issue, but talks fell through on the first day of negotiations.

President Trump has previously met Kim in Vietnam in February 2019 and in Singapore in June 2018 for negotiations on the nuclear program, but no concrete deal on the issue has been achieved so far.

North Korea has drastically expanded its nuclear arsenal in recent years, according to a report in June from the Stockholm International Peace Research Institute. Pyongyang had added up to 20 more nuclear warheads between January 2019 and the start of this year, the Institute said, with North Korea having up to 30 to 40 warheads in total.

Trump’s former National Security Adviser, John Bolton, has said North Korea would never give up its nuclear weapons. Presumptive Democratic presidential nominee Joe Biden has slammed Trump for having met with Kim, with North Korea then labeling Biden as a “rabid dog.”