At an international security conference in Moscow the minister said the "aggressive nature" of the United States had not changed, as current joint US-South Korean military exercises posed a threat to North Korea's security.
The US Armed Forces regularly stages joint drills with the South Korean military at different locations across the country, a constant concern for Pyongyang.
"These exercises aim to eliminate our country's economic development and overthrow our regime," Hyon said.
The defense minister also said that Pyongyang's nuclear deterrence was a "powerful force" for the maintenance of stability in the region.
North Korea first declared it had developed a nuclear weapon in 2009 and the country test-fires missiles on a regular basis.