Pyongyang statement comes after Seoul and Washington announced more than 10 days of large scale military exercises.
In a statement on state media on Sunday, Vice Foreign Minister Kim Son Gyong said the drills and the rhetoric from the allies have pushed tensions to an “extremely dangerous level”.
He said the UN and the international community “will have to strongly urge the US and South Korea to immediately halt their provocative remarks and joint military exercises”.
The statement comes after officials from Seoul and Washington announced on Friday more than 10 days of large-scale military exercises, including amphibious landings, from March 13 to 23.
The allies have said the exercises are defensive and are necessary to counter the rising threats from North Korea’s ballistic missile and nuclear weapons programmes, which are banned by UN Security Council resolutions.
But Pyongyang sees the drills as a rehearsal for invasion.
On Saturday, it blamed Washington for what it called the collapse of international arms control systems and said its nuclear weapons were “the surest way” to ensure the balance of power in the region.
Seoul and Washington also conducted a combined air drill with a US long-range bomber and South Korean fighter aircraft on Friday, the latest in their series of joint training in recent weeks.
The “irresponsible acts” of the allies will only take the regional situation “to a very critical and uncontrollable phase,” Kim warned.
It is regrettable that the UN has been consistently silent on the exercises, which have a “clear aggressive nature,” he added.
Last month Kim issued a statement saying UN Secretary-General Antonio Guterres has been “extremely unfair, unbalanced” on North Korea’s missile tests.