Six-way talks on ending North Korea's nuclear arms programmes are set to resume on Wednesday in Beijing.
US officials have said in recent weeks that Washington is ready to discuss normalising ties and a peace treaty to end the Korean War if Pyongyang follows up on its recent progress in disarmament and completely scraps its atomic arms programme.
Baek Seung-joo, head of North Korean military research at the Korea institute for defence analyses, said this may be a ploy to drive a wedge between the US and its ally, South Korea.
"The comments appear to be intended to exclude South Korea and China in any talks for a peace treaty and to include the subject of removing US troops from the South as part of the talks," he said.
South Korean media has reported that officials are seeking a four-way dialogue, including China, the two Koreas and the US, in order to examine a peace treaty.
The 1950-1953 Korean War ended in a truce. The US, which led UN forces, was a signatory to the armistice as well as North Korea and its ally, China. South Korea did not sign.
The US stations about 30,000 troops in the South to support the country's 670,000 strong military against an attack by the North.
"With the kind of help which we got from the DPRK in the last few weeks, we think we will do our job in a successful way"
Adel Tolba, chief IAEA envoy to North Korea
The statement from North Korea called upon the US to stop joint military drills with the South.
"It is the undeniable and legitimate right of the DPRK to have in place all the necessary self-defensive means to cope with the threat and blackmail of the US in order to protect its right to existence," the statement said.
In a February deal among the two Koreas, China, Japan, Russia and the US, the North agreed to close its antiquated Yongbyon reactor in return for 50,000 tonnes of oil aid.
On Saturday, the International Atomic Energy Agency (IAEA) is set to travel to North Korea, to monitor and verify the shutdown of the Yongbyon facilities, which has the potential to produce plutonium for nuclear weapons.
Adel Tolba, the chief of the IAEA group, said: "With the kind of help which we got from the DPRK in the last few weeks, we think we will do our job in a successful way."